1987/88 - Colorado Department of Education

Transcription

S
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C O L O R A D O AVALANCHE INFORMATION
A
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C
H
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CENTER
T
1 9 8 7 - 8 8
C O L O R A D O
GEOLOGICAL
C O L O R A D O
DEPARTMENT OF NATURAL
1313 S H E R M A N
STREET, R O O M
DENVER, C O L O R A D O
u^ $-V%
J U N E , 1988
SURVEY
80203
715
RESOURCES
C O L O R A D O AVALANCHE INFORMATION
CENTER
ANNUAL REPORT
1 9 8 7 - 8 8
C O L O R A D O
GEOLOGICAL
C O L O R A D O
D E P A R T M E N T O F NATURAL
1313 S H E R M A N
SURVEY
STREET, R O O M
DENVER, C O L O R A D O
715
80203
JUNE, 1988
C
G
S
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L
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A
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Y
RESOURCES
H
Colorado D e p a r t m e n t of Natural R e s o u r c e s
DIRECTOR'S
To Our
S T A T E M E N T
S p o n s o r s and
Colorado Avalanche Information Center
10230 Smith Road
Denver, Colorado 80239
(303) 371-1080
Patrons:
Snow avalanches have always posed a threat to people living in and
visiting the C o l o r a d o m o u n t a i n s , and have c a u s e d , on a regular b a s i s ,
property damage and loss of l i f e . It w a s a problem that begged
s o l u t i o n , and the roots of the C o l o r a d o A v a l a n c h e I n f o r m a t i o n Center
can be traced to a v a l a n c h e research performed by the U . S . Forest
Service in the 1960's and 7 0 ' s .
In 1983 the Center was founded within the Colorado Department of
N a t u r a l R e s o u r c e s on the belief that the impact of a v a l a n c h e hazards on
those l i v i n g , w o r k i n g , v i s i t i n g , or r e c r e a t i n g in the C o l o r a d o
m o u n t a i n s could be lessened by a program of e d u c a t i o n and f o r e c a s t i n g .
In that year a group of sponsors who believed in this m i s s i o n came
together to share the costs of the p r o g r a m .
We have compl eted our fifth year of o p e r a t i o n , and our first year
within the Colorad o G e o l o g i c a l S u r v e y . We feel that it was an
especially success ful y e a r . Some h i g h l i g h t s w e r e :
- Our sponsor s have voiced strong support in carrying out our
mission of public service and s a f e t y .
- We have bui It a credible program in the eyes of the p u b l i c .
- The public has made more use of our a v a l a n c h e h o t l i n e s than
ever before
- Our educati onal efforts and our participation in Avalanche
Back Countr y Safety Week allowed us to reach more people than
ever before
- Our s t a f f , composed of a team of four avalanche professionals,
is stronger than ever .
- Serious ava lanche i n c i d e n t s and a v a l a n c h e - c a u s e d deaths were
down si gnif icantly from a year ago —
in p a r t , no d o u b t ,
because of the e f f o r t s of the Center and its s p o n s o r s .
The C o l o r a d o A v a l a n c h e I n f o r m a t i o n Center is committed to
providing the best possible service to the c i t i z e n s of C o l o r a d o and our
s p o n s o r s . This Annual Report details the a c c o m p l i s h m e n t s of the Center
in 1 9 8 7 - 8 8 .
It is your support that makes the Center possible. We thank you.
;
/
Sirycerely ,
\
Knox W i l l i a m s
Director
C O N T E N T S
Section Page
I. Executive Summary 2
II. Funding and Budget 3
III. Operations 5
IV. Weather and Avalanche Synopsis 7
Snowfall
Avalanches
A v a l a n c h e Hazard and W a r n i n g s
Avalanche Accidents
1
10
12
13
V. Detailed Winter Summary 17
VI. Information Acquisition 32
Daily W e a t h e r , S n o w p a c k , and
W e s t w i d e Data N e t w o r k
Avalanche
Data
VII. Dissemination of Hazard Forecasts 34
Public H o t l i n e s
Radio B r o a d c a s t s
NOAA C o l o r a d o W e a t h e r w i r e
News M e d i a
VIII. Public Education 38
A v a l a n c h e A w a r e n e s s T a l k s and Field
ABC'S Week
A v a l a n c h e C a r d s and B r o c h u r e s
32
33
34
35
36
36
Seminars
38
38
41
IX. Hazard Grading 42
Appendix
A. Sample Avalanche Warnings and Advisories 43
B. Letters and Newspaper Articles 53
List of Tables
Table 1. Monthly snowfall totals 8
Table 2.
A v a l a n c h e s , hazard r a t i n g s , & a c c i d e n t s
Table 3.
A v a l a n c h e w a r n i n g days by month
Table 4.
A v a l a n c h e w a r n i n g days by region
Table 5.
Avalanches reaching highways
T a b l e 6.
Accident statistics
Table 7.
A c c i d e n t s by d a t e , l o c a t i o n , type
T a b l e 8.
A v a l a n c h e c o u r s e s taught
by month
11
14
14
15
15
16
39
E X E C U T I V E
S U M M A R Y
Administration: The Colorado Avalanche Information Center is
managed
by
the C o l o r a d o
Geological
R e s o u r c e s . Knox W i l l i a m s
Survey
is program
of
the D e p a r t m e n t
of
Natural
director.
Funding: The Center is totally cash funded. In FY 87-88, total
revenues were
$112,010.
Housing: The Center is housed at the National Weather Service in
D e n v e r , with
offices
also
at
the U . S . F o r e s t
Service
in Fort
Collins.
Staff: Four forecasters shared the responsibilities of a 7-day
work week
during
the w i n t e r
season
from N o v e m b e r
through
April.
Summary of avalanche events: A total of 1,612 avalanches were
reported
to the C e n t e r
W a r n i n g s were
avalanche
posted
this season
on 32 d a y s
(about
1 5 % below
(4 below n o r m a l ) .
(one a b o v e n o r m a l ) . T h e r e was m i n i m a l
normal).
Five
people
property
Avalanche
died
by
damage.
Avalanche hotlines: The Center maintains avalanche message phdnes
in seven C o l o r a d o
cities
c o n d i t i o n s . Two new
and
towns
phones w e r e
3 0 , 0 0 0 calls were made
for the p u b l i c
installed
to the h o t l i n e s
this
this
to call
season.
for
current
Approximately
winter.
Media contacts: The Center logged 194 contacts with broadcast and
print m e d i a , a c h i e v i n g
an a c c u r a t e
information
profile
and a high
dissemination
for the
of
avalanche
Center.
Public education: Center personnel presented 44 avalanche
awareness
talks and
field
2,673 p e o p l e . We a c t i v e l y
( A B C ' S ) W e e k , held
public
the C e n t e r ' s
seminars, reaching
participated
on January
avalanche
on a p e r s o n a l
in A v a l a n c h e / B a c k
1 1 - 1 8 . We c o n t i n u e d
awareness
level,
Country
to d i s t r i b u t e
c a r d s , b r o c h u r e s , and
Safety
to
hazard
forecast. This
f o r e c a s t , 8% o v e r - f o r e c a s t , and
year
6%
the r e s u l t s w e r e 8 6 % c o r r e c t
under-forecast.
the
posters.
Hazard grading: Each year the Center grades itself on its daily
avalanche
some
F U N D I N G
A N D
B U D G E T
The Colorado Avalanche Information Center is totally cash funded
For FY 1 9 8 7 - 8 8 , total
funding
of $ 1 1 2 , 0 1 0 came
from
the
following
sponsors :
Federal
U . S . Forest
Service
Rocky M o u n t a i n
$50,000
National
Park
$ 2,000
State
Colorado
Department
Colorado
Division
of H i g h w a y s
of P a r k s , S n o w m o b i l e
$20,000
Fund
$ 2,000
Local Government
Pitkin County
$ 3,000
Eagle County
$ 3,000
Summit County
$ 3,000
Town of B r e c k e n r i d g e
$
500
Private
Colorado
Winter
Ski Country
USA
Park R e c r e a t i o n a l
$15,000
$
1,000
$
1,000
$
1,000
Vail A s s o c i a t e s
$
1,000
Steamboat
$
750
$
250
$
200
$
10
Breckenridge
Ski Area
Copper M o u n t a i n
Colorado
Association
Resort
Ski Area
Search
Tenth M o u n t a i n
Miscellaneous
and
Rescue
Trails Association
individual
Carryover from FY 86-87 $ 8,300
TOTAL $112,010
Board
donations
W H E R E
T H E
M O N E Y
C A M E
F R O M
REVENUES
$112,010
Carryover (7.4%)
Misc. (0.4%)
Local Government (8.3%)
Div. of Parks (1.8%)
Rocky Mountain National Park (1.
U.S. Forest Service (44.6%)
Ski Country (17.6%)
Dept of Highways (17.9%)
H O W
T H E M O N E Y W A S
SPENT
EXPENDITURES
$112,010
Administration (4.9%)
Travel (1.596)
Equip & Supplies (2.3%)
Computer upgrade (2.5%)
Data Processing (2.7%)
State Indirect (3.1%)
Carryover (4.5%)
Salaries (58.6%)
Observers (9.2%)
Utilities (10.4%)
O P E R A T I O N S
Administration: The Center is managed by the Colorado Geological
Survey
under
Center
was a d m i n i s t e r e d
Office
of the D e p a r t m e n t
Geological
the d i r e c t o r s h i p
Survey
for
of John W. R o l d .
four
years
of Natural
in April
by
Founded
in
the E x e c u t i v e
Resources
1 9 8 7 . The C e n t e r
1 9 8 3 , the
Director's
before moving
is totally
cash
to
the
funded.
Housing: The Center is primarily housed at the National Weather
Service
Forecast
Fire Weather
Office
in D e n v e r . The
o p e r a t i o n s . Secondary
by the U . S . Forest
Service
in Fort
space
office
provided
is shared
space has also
been
with
NWS
provided
Collins.
Season: The Center operates seven days a week from November
through
April.
Purposes: The purposes of the Center are to:
- monitor
the changing
conditions
- provide
in the C o l o r a d o
twice-daily
telephone m e s s a g e s
- warn of d a n g e r o u s
warning
media
w e a t h e r , snow c o v e r , and
bulletins
mountains
information
(see Data
Sites
to the p u b l i c , via
below);
recorded
(see Section V I I ) ;
avalanche
via
conditions
the NOAA
by issuing
avalanche
Colorado Weatherwire
and
the
news
(see Section V I I ) ;
- provide
specialized
information
-
educational
avalanche
present
public
avalanche
service
- maintain
announcements
a computer
data
e v e n t s , from C o l o r a d o
to s p o n s o r i n g
awareness
t a l k s , s e m i n a r s , and
(see Section
set of m o u n t a i n
and
agencies;
other m o u n t a i n
VIII);
and
weather
and
states
avalanche
(see Section V I ) .
Staffing and Duties: Personnel for the 1987-88 winter were: Knox
Williams
( D i r e c t o r ) , Nick
Logan
Dale A t k i n s . One of
the four
to 4:30
day
pm, o p e n i n g
(Associate
forecasters
November
Director),
was on duty
13th, until
closing
Andy
daily
Loving,
from
on April
and
6:30
30th.
am
The
forecaster
- monitoring
- logging
was r e s p o n s i b l e
mountain
w e a t h e r , snow, and
all incoming
- evaluating
data
for:
data
from
from
field
avalanche
conditions;
observers;
sites and
National
Weather
Service
products;
- making
daily
- updating
- issuing
snow stability
recorded
and
evaluations
telephone m e s s a g e s
terminating
and
forecasts;
twice daily;
a v a l a n c h e w a r n i n g s when
and
warranted.
Data Sites: The Center maintains a network of mountain observation
sites
for
forecast
and
providing
o f f i c e . Altogether
the remainder
supports
Pass;
w e a t h e r , s n o w p a c k , and
contract
it also has access
maintained
talks and
field
at Berthoud
to give
maintain
broad
VIII details our
P a s s , G o t h i c , and
efforts
Red
the
ski a r e a s ,
Center
Mountain
stations
Service.
to many
frequent
coverage
to
l o c a t i o n s . The
above, forecasters
seminars
data
s i t e s : 20 are
from remote weather
to c i t i z e n s , tourists and
a d d i t i o n , forecasters
Section
backcountry
by the Soil C o n s e r v a t i o n
opportunities
personnel
and
to data
E d u c a t i o n : As mentioned
awareness
there are 30 manned
are highway
observers
avalanche
avalanche
g r o u p s , providing
avalanche
avalanche
public
education
practitioners.
contact with news
to current
toward
present
In
media
conditions.
education
and
safety.
W E A T H E R
A N D
A V A L A N C H E
SYNOPSIS
The winter of 1987-88 produced a snow cover in the Colorado
mountains
that
showed
the first
half
of
backcountry
December
from
the w i n t e r , and
snowpack
and
early
late January
two d i s t i n c t
led
to two
January;
o n , and
avalanche
benign
fatal
then
in the second
avalanche
the snow
avalanche
personalities: sinister
events
h a l f . A weak
incidents
cover
in
late
became u n u s u a l l y
dropped
off
in
strong
dramatically.
Seasonal temperatures were near normal throughout the mountains,
but
seasonal
storm
track
snowfall
showed
repeatedly
the Northern M o u n t a i n s
Southern
with
of days with
Avalanche
by a v a l a n c h e
of incidents
causing
was below n o r m a l . Property
north
in w e a t h e r
above-normal
s n o w s . The number
Deaths caused
number
brought
M o u n t a i n s * , which were
below-normal
number
a strong
below
from
the n o r t h w e s t ,
the storm
Warnings
b i a s . The
s n o w s . The C e n t r a l
of reported
favoring
up
a v a l a n c h e s as well
the
were both
long-term
winters
and
t r a c k , wound
in effect
w e r e one above
serious
to south
with
as
the
below
normal.
a v e r a g e , yet
i n j u r y , d e a t h , or property
d a m a g e was p r a c t i c a l l y
nil.
and
for all
the
damage
Snowfall
Table
regularly
1 shows monthly
reported
data
began with a fall season
recent
seasonal
snowfalls
to the A v a l a n c h e
Center
sites
this y e a r . The
that was one of the m i l d e s t
and
that
snow-year
prettiest
in
memory.
On the first of November, there was hardly any snow cover at all
in the high c o u n t r y . N o v e m b e r
snowfall
of the Colorado m o u n t a i n s , except
slightly
above
for
was 6 5 - 9 0 % of normal
the Front Range w h i c h
over
ended
most
up
normal.
* The geographical r e g i o n s called N o r t h e r n , C e n t r a l , and S o u t h e r n
M o u n t a i n s of C o l o r a d o are used e x t e n s i v e l y in this r e p o r t . The N o r t h e r n
M o u n t a i n s extend from the W y o m i n g border on the north to a line from
Denver to Hoosier P a s s (just south of B r e c k e n r i d g e ) to G l e n w o o d S p r i n g s
as the southern b o u n d a r y . T h i s b o u n d a r y roughly follows the 1-70
c o r r i d o r , but dips south in the area of B r e c k e n r i d g e to i n c l u d e the
Ten Mile R a n g e . The C e n t r a l M o u n t a i n s extend south from t h i s line
through D e n v e r - H o o s i e r P a s s - G l e n w o o d S p r i n g s to a s o u t h e r n b o u n d a r y
line from Pueblo to M o n t r o s e . The S o u t h e r n M o u n t a i n s lie b e t w e e n this
P u e b l o - M o n t r o s e line and the New M e x i c o b o r d e r .
Table 1.
NORTHERN
1987-88 s n o w f a l l t o t a l s in inches (percents
sites with 10 or m o r e years of r e c o r d )
Feb Mar
29
47
33
54
46
54
54
47
50
70
68
41
51
46
49
41
57
52
61
84
82
58 105
71
85
47
53
47
43
30
44
40
39
35
54
60
84
57
41
55
66
61
70
61
55
64
84
83
66
74
47
46
42
30
51
51
51
37
43
46
57
89
90
43
62
21
22
22
43
25
26
40
42
40
25
53
41
50
40
39
37
48
60
61
50
56
80
29
15
18
33
58
30
20
19
Apr
Total
Dec-Mar
% of
Total
Norm N o v - A p r
for
% of
Norm
38
31
30
34
49
36
37
44
30
55
30
202
217
188
252
193
189
197
251
309
313
287
188
97
107
268
308
251
96
102
90
105
340
125
109
123
254
113
316
95
MOUNTAINS
ASPEN H I G H L A N D S
ASPEN MOUNTAIN
CRESTED BUTTE
GOTHIC
MONARCH
SNOWMASS
SUNLIGHT
SOUTHERN
Dec Jan
are
MOUNTAINS
A R A P A H O E BASIN
B E R T H O U D PASS
BEAR LAKE
BEAVER CREEK
BRECKENRIDGE
COPPER MOUNTAIN
KEYSTONE
LOVELAND
MARY JANE
STEAMBOAT
VAIL
WINTER PARK
CENTRAL
Nov
of n o r m a l
31
52
49
152
150
134
236
207
170
179
92
76
91
117
91
MOUNTAINS
RED MOUNTAIN
TELLURIDE
PURGATORY
WOLF CREEK
PASS
42
57
33
187
132
142
192
262
88
63
December
snowfall
showed
large
variability
In the Northern M o u n t a i n s , values ranged
in the Central M o u n t a i n s
h o w e v e r , saw normal
from
over
distances.
7 5 - 1 1 8 % of n o r m a l ,
the range was 6 5 - 1 3 8 % . The
snows
short
Southern
while
Mountains,
throughout.
January proved to be an active month for weather and avalanche
events.
Snowfall
was heavy: Monarch
n o r m a l , while almost
n o r m a l s . January
snowpack:
warmer
snowpack
which
the list with
sites accumulated
was also the pivotal month
following
abruptly
all other
topped
1 8 8 % of
1 0 5 - 1 3 5 % of
their
in the d e v e l o p m e n t
of
a series of storms in m i d - m o n t h , the w e a t h e r
and created
persisted
a thick, strong
until
the end
layer
in the
the
turned
mountain
of the w i n t e r .
February marked the start of a weather trend which brought
repeated
Central
storms into
and
the Northern
Mountains
Southern M o u n t a i n s . S n o w f a l l s
1 3 3 - 8 4 % of n o r m a l , while
at the expense
in the North
of
the
ranged
they were 6 6 - 5 1 % in the C e n t r a l
and
from
Southern
Mountains.
This pattern of snowfall continued in March. The Northern
Mountains
got
Mountains
managed
March
1 1 6 - 8 8 % of n o r m a l , while
only
the Central
7 8 - 6 1 % , and Wolf Creek
and
got but
Southern
2 1 % -- its
driest
ever!
April saw a typical mix of spring weather; snow showers and warm
days
for
the majority
few d a y s . April
snows averaged
Central M o u n t a i n s
For
totals
of the m o n t h , and
recorded
the seasonal
a spring
storm
during
8 0 - 8 5 % in the N o r t h , but Gothic
1 5 0 % of
trend, note
in Table
e v i d e n t , as the Northern M o u n t a i n s
1 the
bias in s n o w f a l l
attained
Only
snowfall
of N o v e m b e r - A p r i l , and
from
the D e c e m b e r - M a r c h
long-term
this longer
totals.
snowfall
is
9 0 - 1 2 5 % of normal
the Southern M o u n t a i n s ,
sites have
in
the
percent-of-normal
the C e n t r a l M o u n t a i n s , 7 6 - 1 1 7 % ; and
data
last
normal.
for D e c e m b e r - M a r c h . The n o r t h - s o u t h
four
the
records
season
for
showed
clearly
snows;
63-88%.
the six
months
little
change
Avalanches
A total
of
from November
average
of
through
1,900
the avalanche
included
1,612
avalanches
was
A p r i l . This number
avalanches. Table
t o t a l . January
a 10-day
reported
siege
was
in which
is roughly
2 shows
the
to the A v a l a n c h e
1 5 % below
the m o n t h l y
big month
Center
the
distribution
for a v a l a n c h e s ;
520 a v a l a n c h e s
were
reported
of
it
to
the
Center .
There were two main reasons why the avalanche total was below
normal
this w i n t e r . F i r s t , there was v i r t u a l l y
high country
environment
favorable
until early
to m i d - N o v e m b e r . T h i s meant
for d e v e l o p i n g
as it was a year
snow grain
that grows
dangerous avalanche
depth
ago.
hoar
(Depth
hoar
cover
in early
in
cover
was not
that
and
last
November
often
year
that
the
the
is a l a r g e , w e a k ,
snow
conditions.) Remember
cover
that
in the s n o w p a c k
in a c o l d , shallow
with a 2 to 3-foot snow
no snow
nearly
unstable
leads
started
turned
as
to
out
entirely
to
depth hoar .
Depth hoar, did in fact, develop in the snow cover which built up
in N o v e m b e r , but the grain
nearly
as great as they
hinted
that
avalanches
were
the C o l o r a d o
prone snow cover
that
size and
of this layer
last y e a r . T h i s was a good
m o u n t a i n s would
plagued
(76, as shown
thickness
2 ) , but D e c e m b e r
not
sign, because
the weak
us last y e a r . N o v e m b e r
in T a b l e
a v a l a n c h e s ) as the d e v e l o p i n g
be spared
were
avalanche-
produced
very
was a c t i v e
(349
snow cover was still o v e r a l l
it
shallow
few
and
weak.
The second main reason for the subnormal avalanche total was a
dramatic
warmup
in the w e a t h e r
slides at the t i m e , but the
on January
lasting
into the s n o w p a c k . The a v a l a n c h e
fell to fractions of their
deep enough
to produce
normal
totals
was
It caused
that
a few
strength
was
for F e b r u a r y , M a r c h , and
wet
put
April
v a l u e s . By A p r i l , snow d e p t h s w e r e
a significant
10
effect
26-29.
cycle of w e t - s l a b
avalanches.
not
Table 2.
1987-88 w i n t e r
accidents.
summary
of a v a l a n c h e s , hazard
days
and
Dec
Jan
Feb
Mar
Apr
TOTAL
No. of avalanche warning periods 0
2
3
2
1
0
8
No. of days with warning in effect 0
8
17
5
3
0
33
349
680
156
211
140
1612
22
30
20
28
23
138
Nov
No. of observed avalanches 76
No. of days with 1 or more avalanches 15
Northern M o u n t a i n s
N o . of days w i t h :
low hazard
moderate hazard
high hazard
extreme hazard
0
2
0
0
7
17
7
0
0
11
20
0
11
14
4
0
11
18
2
0
23
7
0
0
62
69
33
0
Central Mountains
low hazard
m o d e r a t e hazard
high hazard
extreme hazard
10
2
0
0
7
17
7
0
0
8
23
0
10
16
3
0
18
13
0
0
24
6
0
0
69
62
33
0
Southern Mountains
low hazard
m o d e r a t e hazard
high hazard
extreme hazard
10
2
0
0
8
16
7
0
0
6
25
0
14
13
2
0
21
10
0
0
25
5
0
0
78
52
34
0
4
2
1
1
0
0
0
15
7
2
0
2
0
0
10
7
3
0
3
1
0
1
0
0
0
0
1
0
7
4
0
1
0
0
0
5
0
0
0
0
1
0
42
20
6
2
5
3
0
Avalanche accidents
people caught
people partly buried
people buried
people injured
people killed
vehicles caught
property sites damage
11
Avalanche Hazard and Warnings
Tables
and
2, 3, and
warning
4 present
several
days this s e a s o n . T a b l e
(low, m o d e r a t e , h i g h , e x t r e m e ) for
Mountains
show
on a monthly
the same
trend
D e c e m b e r , mostly
trend
" m o d e r a t e " ; and
hazard, which
figures
reflects
the daily
for
all
in N o v e m b e r
hazard
and M a r c h
" l o w " . T h e r e were
the lack of
hazard
ratings
Southern
three m o u n t a i n
it was m o s t l y
in J a n u a r y , mostly
that F e b r u a r y
April was mostly
2 shows
the N o r t h e r n , C e n t r a l , and
in the h a z a r d :
r e v e r s e s , such
low" and
b a s i s . The
l o o k s at the a v a l a n c h e
areas
"low";
" h i g h " . Then
were mostly
i n t e n s e , prolonged
the
"moderate
no days with an
in
to
"extreme"
storms.
Table 3 shows a monthly summary of warning days for the 1987-88
s e a s o n , plus the p r e v i o u s
the hazard
was rated
warnings
average number
day
high and an A v a l a n c h e W a r n i n g
issued
issued
13 s e a s o n s . (A w a r n i n g
on 32 d a y s ,
in N o v e m b e r
of w a r n i n g
and
four
is one on
was
which
issued.)
days below a v e r a g e . T h e r e were
A p r i l , while January
had
twice
no
the
days.
Table 4 breaks the warning days this season into regional
statistics
for the N o r t h e r n , C e n t r a l , and
typical year
but this year
reflects
the S o u t h e r n M o u n t a i n s would
S o u t h e r n M o u n t a i n s . In a m o r e
have
it was the N o r t h e r n M o u n t a i n s
the s e a s o n a l
north-south
snowfall
the most w a r n i n g
which had
the m o s t ,
b i a s a c r o s s the
days,
which
state.
Table 5 shows the impact of avalanches this season on Colorado
mountain
h i g h w a y s . It lists the number
both natural and a r t i f i c i a l l y
The total of
15 natural
n o r m a l . The main
reason
the a v a l a n c h e - p r o n e
5 5 0 , and Colo
triggered
releases
and
of e v e n t s and
avalanches
6 triggered
for this w a s the light
highways
in the
110.)
12
d a t e s on
reached
which
highways.
e v e n t s is far
snowfall
Southern M o u n t a i n s
that
below
affected
(U.S. 160, U.S.
Avalanche Accidents
The
last
involving
same
part
people
of T a b l e
and
s t a t i s t i c s with
was slightly
buried
was above
one above
showed
damaged
worse
property
than
over
a monthly
breakdown
1987-88, while
annual
average:
n o r m a l , and
improvement
in
long-term
the l o n g - t e r m
this
2 lists
Table
the n u m b e r
of
of
people
people
year. Finally,
there
of
caught
killed
a v e r a g e . H o w e v e r , all a c c i d e n t
avalanches
6 compares
a v e r a g e s . The winter
the n u m b e r
last
of
—
these
1987-88
and
5 —
partly
was
categories
were no property
sites
year.
Table 7 lists all accidents reported to the Avalanche Center this
w i n t e r . Note
and January
that
there were
1 0 ) , and
$ 1 0 , 0 0 0 ) occurred
only
the only
on January
two
damage
9 when
fatal
of
the
a car
accidents
year
(on D e c e m b e r
29
(approximately
was hit
on Berthoud
Pass.
This synopsis has presented a general and statistical overview of
the 1987-88 winter
s e a s o n , with T a b l e s
the s e a s o n . For a m o r e
should
continue
detailed
to the next
1-7
description
showing
of e v e n t s , the
s e c t i o n , the D e t a i l e d
13
different
Winter
aspects
reader
Summary.
of
Table 3.
A 14-year summary of avalanche warning days
Winter Nov Dec Jan Feb Mar Apr Total
1974-75
1975-76
1976-77
1977-78
1978-79
1979-80
1980-81
1981-82
1982-83
1983-84
1984-85
1985-86
1986-87
1987-88
0
3
0
2
0
6
0
4
1
8
2
12
0
0
9
4
4
5
13
5
6
8
7
15
10
3
0
8
Total
Average
38
2.7
97
6.9
Table 4.
10
12
5
8
0
9
6
3
14
3
6
12
6
4
16
6
7
7
12
20
2
3
3
3
4
0
15
17
115
8.2
98
7.0
15
4
5
15
9
5
16
4
16
12
12
0
5
3
2
0
2
0
5
4
5
0
5
9
3
0
0
0
121
8.6
35
2.5
52
29
23
37
39
49
35
22
46
50
37
27
26
32
504
36.0
Avalanche warning days* by region, 1987-88 (dates in
parentheses)
Region Nov Dec Jan Feb Mar Apr Total
(5-6)
Northern
Mountains
Days
(11-14)
(9-14)
(23-26) (23-26) (10-11) (24-26)
0
Central (5-14)
Mountains
8
12
2
3
0
25
0
0
19
(23-26) (23-26) (10-11)
Days 0 4 14 2 0 0 20
Southern (5-14)
Mountains
Days
(23-26) (18-20)
0
4
13
(3-4)
2
Total 0 16 39 6 3 0 64
*A warning day is one on which the hazard was rated high and a
warning was issued.
14
Table 5.
Avalanches
reaching
Colorado
highways,
1987-88
Highway Location Natural aval. Triggered aval.
1-70 Vail Pass 1 - Jan. 11
U.S. 6 Loveland Pass 4 - Jan. 23 5 - Nov. 19
Mar.
2, 4, 24
Jan.
Mar.
Dec.
Jan.
Feb.
23
1 1 , 2 0 , 21
28
13,24,31
25
U.S. 40 Berthoud Pass 1 - Jan. 9
U.S. 50 Monarch Pass 1 - Jan. 6
U.S. 160 Wolf Creek Pass 1 - Feb. 3
U.S. 550 Red Mountain Pass 6 - Nov. 17
U.S. 550 Coal Bank Hill 1 - Feb. 3
Colo. 110 Cement Creek 1 - Jan. 13
Total: 21 avalanches; 15 natural and 6 triggered.
Table 6.
Summary
s t a t i s t i c s of C o l o r a d o
avalanche
victims
1970-87 (17 winters) 1987-88
People caught 575 34 42
People partly buried
People totally buried
People injured
People killed
Total
Average
160
109
54
67
9
6
3
4
15
Total
20
6
2
5
Table 7.
Colorado
avalanche
accidents, 1987-88
Date
Location
Details
10/25
11/7
11/8
11/14
12/1
Telluride
Gothic
Independence
Telluride
Breckenridge
1
1
1
1
1
12/6
12/8
12/11
12/11
12/11
Loveland Pass
Aspen
Snowmass
Vail
Vail
2
1
1
1
1
ski tourers caught; 1 ptly buried
p a t r o l l e r caught
p a t r o l l e r caught & ptly buried
lift skier in closed area ct & pb
lift skier in closed area c a u g h t
12/12
12/20
12/23
12/29
12/29
Loveland Basin
J o n e s Pass ( n e a r )
Snowmass
Berthoud Pass
Timberline
1
1
1
1
1
patroller caught and ptly buried
ski tourer caught
p a t r o l l e r caught & ptly buried
ski tourer caught & ptly buried
lift skier in closed area c a u g h t
12/29
1/5
1/7
1/7
1/9
Berthoud Pass/2nd Ck.*
Hoosier Pass
Snowmass
Telluride
Berthoud Pass
2
2
1
1
1
ski tourers caught, buried & killed
ski t o u r e r s caught & ptly buried
patroller caught & ptly buried
car and o c c u p a n t ct & ptly buried
1/10
1/16
1/18
2/3
3/5
Castle Ck (nr A s h c r o f t ) *
J o n e s Pass
Aspen H i g h l a n d s
Wolf Creek Pass
Vail
3
1
1
1
1
ski t o u r e r s c a u g h t , buried & killed
s n o w m o b i l e r caught & ptly buried
i n - b o u n d s skier c t , ptly bur & inj
vehicle and driver caught
3/8
3/9
3/9
3/19
3/27
S t . M a r y ' s Glacier
Aspen Snowcat T o u r s
Telluride
Greywolf Mountain
Chair M o u n t a i n ( n e a r )
2
1
1
1
1
ski t o u r e r s caught
guide caught & ptly buried
o u t - o f - b o u n d s lift skier c a u g h t
snowshoer caught & ptly buried
ski tourer c t , ptly bur & injured
4/2
4/3
4/7
4/9
4/16
Vail Pass
Telluride
Red M o u n t a i n Pass
Loveland Pass
Copper M o u n t a i n
2
1
1
1
1
Pass
16
(*
= fatal
accident)
ski tourer caught & buried
hiker caught and injured
patroller caught
snowmobiles buried
ski tourer caught
car ct & d a m a g e d ; 2 o c c u p a n t s
ski tourer caught
patroller caught
ct
D E T A I L E D
W I N T E R
S U M M A R Y
The following narrative is a month-by-month description of weather
trends and
activity
events of
that
developing
the
resulted
mountain
1987-88 w i n t e r
from
season
the i n t e r a c t i o n
and
the
between
avalanche
the weather
and
the
snowpack.
October
October
clear
weather
s k i e s , mild
was what many
t e m p e r a t u r e s , and
sat over
the m o u n t a i n s
Colorado
until
the
w e s t . This 4-day
M o u n t a i n s , but
of us have come
keeping
any
few s t o r m s . A high
h i n t s of
12th when an u p p e r - l e v e l
storm
1-1/2
left
inches
just
to C o l o r a d o
. 2 0 " of water
of m o i s t u r e
pressure
the upcoming
storm
fell
winter
approached
in the
for:
ridge
out
from
of
the
Northern
in several
a r e a s of
the
San
Juan M o u n t a i n s .
Another week of beautiful mild days followed this first winter
storm, then another
short-wave
Colorado
from the southwest
Colorado
another week
elevations;
of stormy
weather
on the 23rd. T h i s storm
became
of variable wet w e a t h e r . Rain
unseasonably
snow cover
to
m i l d , causing
came
gave
into
Southern
fell at
snow, at high e l e v a t i o n s . Skies cleared
temperatures
elevation
impulse
lower
on the 31st
most
of the
and
high-
disappear.
Early season snows brought a few eager folks into the backcountry,
and
the first a v a l a n c h e
incident
of the season
occurred
T e l l u r i d e . A ski tourer
and his dog were c o m p l e t e l y
slide, but were
recovered
luckily
their c o m p a n i o n s . Though
e q u i p m e n t , they
found
uninjured
by
on the 25th
buried
the quick
in a small
actions
none of the party m e m b e r s were c a r r y i n g
the victim
by f r a n t i c a l l y
probing
near
with
of
rescue
their
ski
poles.
November
November
began with
only a s c a n t , patchy
country. This was remarkably
different
from
snow cover
last
y e a r , when
began with a snow cover
that averaged
about
that at this early
the potential
for d e v e l o p i n g
layer of depth hoar
17
date
at the ground
3 feet
was not nearly
in the
high
November
in d e p t h . It
appeared
a dangerously
as great
as a year
deep
ago.
The unseasonably
October
of wet
were briefly
snow
Colorado
to Wolf
warm
t e m p e r a t u r e s which
disrupted
Creek
were
very
warm
temperatures
by a fast-moving
on November
got a few flurries
the
storm
2nd. Other
from this storm,
l i g h t . By the afternoon
returned
began
last day
which
mountain
brought
areas
but a c c u m u l a t i o n s
high
16"
of
of
of the 3rd, this storm moved
to the Colorado
of
snow
east
and
country.
Dry, warm days continued throughout the first half of November.
The mountain
reported
snowpack
became
thin, with only
a shallow
in a few h i g h - e l e v a t i o n , n o r t h - f a c i n g
snow cover
starting
being
zones.
After this dry period, the first of several storms to move through
Colorado
began
mountains
energy
west
shifted
the
of the Continental
to the Front
in Rocky M o u n t a i n
the
storm
14th. This storm
National
diminished
behind
the center
Central
and
R a n g e . By the
the next
3 4 " on Mount
of the
storm's
received
fell
weather
areas of
generous
fallen
intensity
7-10" of snow
18th, several
also had
the
E v a n s . The
few days as unsettled
of the storm. By the
in
15th, 1 7 " of snow had
16th, but another
M o n a r c h , with
4-6" of snow
D i v i d e , but then most
Park and
by the
over
dropped
in
of
the
lingered
the
snows;
3 3 " , got the m o s t .
Several days of toasty weather returned to Colorado after this
storm, and
most mountain
4 0 ' s . Another
storm
snow
for
came
short-wave
in from
disturbance
high
entered
the n o r t h w e s t , giving
by the 25th, while
the same
areas recorded
the Central
temperatures
Colorado
in the mid
on the 22nd.
and Southern M o u n t a i n s
only
This
6-11"
got
of
2-4"
period.
The last week of the month attempted to re-establish above normal
t e m p e r a t u r e s , but another
Thanksgiving
into
south
inches
developed
Day, the 26th, a mild
the Central
received
storm
and
only a T - l " . W i n d s stayed
of new snow were added
this storm
southwest
wind
Southern M o u n t a i n s , while
of C o l o r a d o . As skies began
followed
to the s o u t h w e s t . On
to clear
into C o l o r a d o , and
2 - 1 0 " of
the N o r t h e r n
light as the storm
to the storm
18
brought
Mountains
center
stayed
on the 2 7 t h , a few
s t a k e s . A cold
well
more
airmass
the last days of the
snow
month,
had
though
sunny, remained
teens and mid
cold
with daytime
temperatures
staying
in
the
20's.
The Avalanche Center opened November 13th. No major avalanche
cycles
lack
and
no Avalanche
of sustained
fairly
productive
avalanche
was partly
partly
buried
Telluride
during
s n o w f a l l . S t i l l , the few storms
during
their
incidents were
tourer
issued
reported
buried
that
did
due
to
arrive
v i s i t s . 76 a v a l a n c h e s
and
the
were
three
to the C e n t e r : on the 7 t h , a ski
near G o t h i c ; on the 8 t h , a ski tourer
on I n d e p e n d e n c e
was injured
brief
the month
P a s s ; and
when he was swept
on the 14th, a hiker
off a 40-foot
was
near
cliff.
Snowfall totals for the month were well below normal in most areas
of the s t a t e . Arapahoe
72%;
and
from
upslope
Basin
reported
6 3 % of n o r m a l ; V a i l , 6 5 % ; G o t h i c ,
Copper M o u n t a i n , 9 1 % . H o w e v e r , two Front
storms and
1 0 5 % , and Winter
managed
above-normal
Range
sites
s n o w s : Berthoud
benefitted
Pass
got
P a r k , 1 1 0 % of n o r m a l .
At this point in the season, the snow cover was shallow in all
mountain
likely
areas of C o l o r a d o . The
depend
metamorphosed
(which
strong
and
d r y ) , this would
layers
underneath
last year
could
season would
dangerous
happen again
over and
happen
layer
not be nearly
so
would
it
of depth
if December
hoar
were
season. If, however,
nullifying
if December
season
snow c o v e r . If
be a severe a v a l a n c h e
formed, bridging
(which would
of the a v a l a n c h e
to this early
into a l a s t i n g , d e e p , and
happened
especially
the
on what happened
severity
the depth
were warm
and
hoar
snowy),
then
avalanche-prone.
December
The
weather.
feet
first week
of December
The mountain
in the Northern
snowpack
and
brought
was shallow
M o u n t a i n s . The mild weather
gradient
(TG) development
early
Some o b s e r v e r s
December
because
reported
this posed
of the absence
t r e e l i n e . On December
and
their
little danger
of a s l a b , except
1, a ski patroller
19
of depth
snowpack
D e c e m b e r , with
1-1/2
contributed
the growth
fall-like
in early
Central M o u n t a i n s , and
Southern
cover.
m i l d , dry,
to 3 feet
to strong
hoar
going
the
temperature-
in the
snow
to all TG g r a i n s . In
to the backcountry
in isolated
in
1-2
traveller
pockets
at B r e c k e n r i d g e
was
above
caught
while
ski
packing
snowboarder
and
and
a steep
s l o p e , and
skier were
on the 6th on Loveland
c a u g h t . The
the skier was partially
snowboarder
escaped
Pass a
to the
side,
buried.
The mild weather ended on the 8th as the first of three fast-moving
short
waves
Mountains,
brought
through
orographic
the
12th. The
to the Northern M o u n t a i n s
Central Mountains
Mountains
first
to the
disturbance
in g e n e r a l , but Beaver
received
reported
s n o w s , primarily
Northern
brought
Creek
reported
up to 1 0 " (at M o n a r c h ) , w h i l e
1-5". An Aspen
ski
patroller
3-6" of
the
was caught
snow
1 7 " . The
Southern
by a
small
slide on the 8 t h .
Observers reported additional snow in the Northern Mountains and
increased
the
west
winds as the second
10th. Most
short wave crossed
sites reported
to northwest
winds
2-5", but Mary
began to load
several
a c c i d e n t s on the
11th.)
maximum
gust of 92 mph on the
Jane received
starting
M i n e s Peak
over
zones
9".
Strong
(which would
at Berthoud
on
Pass had
cause
a
10th.
On December 11th observers reported continued strong winds and 2-6"
in the Northern M o u n t a i n s
from
the third
short w a v e . The
Mountains
reported
1-2" g e n e r a l l y , but Monarch
Mountains
remained
dry. An Avalanche
and was upgraded
Continental
to the season's
Divide
a f t e r n o o n . The Warning
would
7". The
Southern
was issued
near
midday
first Avalanche Warning
(for
the
between Winter
stay
Advisory
received
Central
Park and
Arapahoe
in effect
until
B a s i n ) later
the
in
the
14th.
The strong winds loaded snow onto steep slopes, increasing the
possibility
accidents
of triggered
r e l e a s e s , and
o c c u r r e d . P a t r o l l e r s were caught
S n o w m a s s and
L o v e l a n d ; and
skiers triggered
partially
avalanche
releases
at Vail
in closed
were
reported
to the
occurred
a r e a s , resulting
During
11th,
partially
two incidents
buried. All were u n i n j u r e d .
avalanches
and
on the
four
buried
at
when
lift
in one skier
the storm
period,
both
being
65
Center.
On the 12th the Northern Mountains reported 1-6" of new snow, the
Central Mountains
a g a i n . That
a T - 2 " , while the Southern M o u n t a i n s
afternoon
brought
clearing
20
skies and
arctic
went dry
air
that
once
kept
temperatures
cold
until
temperatures
that did
the
15th. Many
not even
reach
observation
sites
reported
high
zero.
Fair weather continued and temperatures moderated through the 18th
as C o l o r a d o
and
sat in the doldrums of
some
light
fairly
orographic
split
flow. This kept
the
Northern
dry, but the Southern M o u n t a i n s
snows from the southwest
did
receive
flow.
A broad trough centered over Colorado on the 19th-20th brought good
orographic
snows to all m o u n t a i n s
with o b s e r v e r s
19th. The next day
the Central and
while
Mountains
the Northern
20th at Jones Pass
large hard
a large
(near
received
Berthoud
2-11". During
injury
3-6" on
reported
this storm
P a s s ) , a ski tourer
slab a v a l a n c h e , but escaped
block of
reporting
1-6",
on
was caught
by riding
the
the
in a
out the slide
on
snow.
December's snowiest period occurred between the 22nd-28th, as a
strong
storm
southward
developed
it tapped
H a w a i i , causing
a band
abundant
Advisory
was issued
the 22nd
reported
tensioned
northwest
of C o l o r a d o . As the storm
of subtropical
snowfall
2-6" with w i n d s of
raised
the hazard
t r e e l i n e . On the 23rd
the Northern
snow;
the Central M o u n t a i n s , a T - 8 " ; and
from
Avalanche
developed. Observers
15-25 m p h . The wind
above
starting
extending
for all m o u n t a i n s . An
on the 21st as this system
slab layer which
Even where
moisture
dipped
to high
Mountains
for all
reported
the Southern
snowfall was l i g h t , w i n d s of 20-35 mph
created
on
a
mountains
2-13" of
new
Mountains, 0-2".
transported
snow
into
zones . -
The combination of new snow and winds necessitated December's
second
that
Avalanche Warning
day at Snowmass
b u r i e d , and
a bank
W i n d s decreased
Creek
and
received
positioned
slide
briefly
closed
for all m o u n t a i n s . On
were caught
and
partially
U . S . 550 on Red M o u n t a i n
on the 24th, but snow
2-9" in the Northern M o u n t a i n s
and
Pass.
continued
to
generally
2-6"
Southern M o u n t a i n s , but P o w d e r h o r n , P u r g a t o r y , and
1 4 " , 1 4 - 1 / 2 " , and
itself
on the 23rd
two ski p a t r o l l e r s
substantially
a c c u m u l a t e , with
the Central
to be issued
just
16", respectively.
As the
day and
21
the
26th. The W a r n i n g
Wolf
low
south of C o l o r a d o , it kept c a l m , cold
for C h r i s t m a s
in
was
air
over
terminated
the afternoon
t r i g g e r e d , were
of
reported
the 26th. More
during
than
the warning
160 s l i d e s ,
mostly
period.
As the low-pressure center moved into eastern Colorado on the 27th,
snowfalls
got only
were concentrated
a few i n c h e s .
southwest
releases.
near
28th dawned
starting
several
(gusting
above
that
slope while
the
c l e a r , but by the
to 5 0 ) sprang
zones enough
slides
was rated m o d e r a t e
and
the eastern
In a d d i t i o n , control work
released
hazard
The
winds of 20-35 mph
f r o n t . This loaded
Pass
along
on the Seven
briefly
on
US 6. The
for all m o u n t a i n s with
of
the
next
natural
Sisters
closed
29th
up ahead
to cause a few
mountains
Loveland
avalanche
pockets of high
hazard
treeline.
Several accidents occurred on the 29th. First, a lift skier at
Timberline
skied
uninjured.
Second, a ski tourer
on Berthoud
into a closed
P a s s , triggering
third, it was probably
of the season
them
January
a bank
on the 29th
of Berthoud
slide
that
ski tourer
found
victim
the second
in terrain
on January
that
a high a v a l a n c h e
at the
buried
an a v a l a n c h e
until
in
that
the
him.
Second
totally
1st
of
a s k i , still attached
to
(This a c c i d e n t
had
And
fatalities
traveling
d e b r i s . R e s c u e r s with
2nd.
escaping
cut on U . S . 40
partially
the A v a l a n c h e Center
hazard
road
ski tourers
spotted
out of the a v a l a n c h e
but
the first a v a l a n c h e
P a s s , triggered
v i c t i m , sticking
having
that
both. The accident was not discovered
when a passing
timberline
a slide
cut across a steep
o c c u r r e d . Two experienced
C r e e k , just north
buried
a r e a , triggering
one
probes
occurred
designated
above
as
time.)
The month ended with a broad trough settled over Colorado on the
30th-31st;
the
1-3" of snow
fell
in all m o u n t a i n s
on the 3 0 t h , and
1-7" on
31st.
December snowfalls were quite variable. In the Northern Mountains,
Arapahoe
Basin was 7 5 % of n o r m a l ; B r e c k e n r i d g e , 7 7 % ; S t e a m b o a t , 8 1 % ;
Copper M t n . , 9 5 % ; V a i l ,
118%.
1 0 0 % ; Berthoud
Pass,
In the Central M o u n t a i n s , Crested
Gothic,
snowpack
both T e l l u r i d e
was typically
and Wolf
unstable
Creek
were
1 3 8 % . In the
Southern
1 0 0 % of n o r m a l . The
in all m o u n t a i n
22
Park,
Butte was 6 5 % ; S u n l i g h t , 8 1 % ;
1 0 2 % ; Aspen M t n . , 1 1 4 % ; and M o n a r c h ,
Mountains,
1 0 9 % ; and Winter
a r e a s , as
December
snowfalls
to build
were not heavy
a strong
349 slides
Fifteen
buried
being
enough and
temperatures
not warm
enough
snow c o v e r . The month was active a v a l a n c h e - w i s e ,
reported
to the Center
people were c a u g h t , seven were
and
were
(233 from
partly
the
with
22nd-28th).
buried, and
two
were
killed.
January
The month of January
only
the single
temperatures
digits and
plummet
develop
temperatures
clear
snowy
to see the first
period
for
reached
skies at night
below z e r o . By the 4th
beginning
into a long
out cold: high
low t e e n s , while
to well
Southern M o u n t a i n s were
soon
started
the C e n t r a l
helped
and
flakes of what
the C o l o r a d o
would
mountains.
On the morning of the 5th up to 14" of fresh snow had fallen at
some
l o c a t i o n s , and
-- for
the first Avalanche Warning
all m o u n t a i n s
avalanches
country
reached
-- in a n t i c i p a t i o n
P a s s . By the next day
and
and
were
dropped
showed
that
fresh
a small
snow
from the warning
close
partly
little
buried
snowfall.
P a s s , and
were reported
slide closed M o n a r c h
occurred,
Hoosier
in the
Central
Pass
skiers at Snowmass and
for
half
Mountains
on the
including
Three
on
to the n o r t h , the N o r t h e r n
had
issued
two c r o s s -
in an a v a l a n c h e
area on the 6th. A tally
to 180 a v a l a n c h e s
buried
partly
16-30" accumulations
Southern M o u n t a i n s , and
an h o u r . With
of continued
U . S . 550 over Red M o u n t a i n
skiers were caught
of the month was
7th
two small
slides
Telluride.
The Warning remained in effect in the Central and Southern
M o u n t a i n s , and
by the morning
the second
Berthoud
nearly
again and
t i m e . Later
of the 9 t h , snow caught
they were
included
that m o r n i n g , a car and
Pass by the Stanley
avalanche
only
minor
just
a bumpy, loud, noisy
thing
I noticed
funny
because
i n j u r i e s . He described
was the windshield
driver
d a m a g e d , but
his ordeal
ride down; then
were
the car
A lucky
area
caught
the road
the driver
s t o p p e d , and
motorist
it
for
on
for
escaped
by s a y i n g , "It
w i p e r s were g o i n g , but
there was no w i n d s h i e l d . "
the
in the w a r n i n g
path that closed
four h o u r s . The car was severely
with
up to
was
the
first
looked
indeed!
But January was not without its share of tragedy. The Avalanche
Warning
continued
as snowfall
persevered
23
and
s t r o n g e - w i n d s began
to
compound
the d a n g e r o u s
cross-country
they
avalanche
skiers and
triggered
a dog lost
near Pearl
avalanche
third
was not wearing
rescue
teams were
forced
conditions
and a threatening
safety.
recovered
as of
the
10th,
three
in an a v a l a n c h e
that
of A s p e n . Two of the v i c t i m s , who
a beacon
and
area
avalanche
that recovery
c o n d i t i o n s were deemed
lives
b e a c o n s , were
out of the search
It was decided
their
Pass south
were wearing
victim
s i t u a t i o n . On Sunday
recovered
could
not
the next
hazard
that
day.
The
be l o c a t e d .
day
Rescue
by a d v e r s e
weather
that
jeopardized
their
efforts would
begin again
when
s a f e . (The w o m a n ' s
body
had
still
not
own
been
mid-May.)
The Warning continued another four days before its termination on
January
and
14th. Four more
Red Mountain
slides reached
P a s s e s , and C o l o r a d o
was o v e r , but no additional
Colorado highways
110 north of S i l v e r t o n ) before
a c c i d e n t s were
r e p o r t e d . After
days of a v a l a n c h e w a r n i n g s , the final count
with
three
This would
(Vail, Monarch,
included
eight
f a t a l i t i e s , one car d e s t r o y e d , and
520 recorded
be the worst
winter.
avalanche
bout of the
it
a grizzly
people
10
caught
avalanches.
There was only a brief reprieve, if it can be called that, before
the next
system
moved
cold
front
kept
the avalanche
night
gust
that was due to pass through
reached
of
into C o l o r a d o . Strong
hazard
velocities
w i n d s ahead
of
late on the
15th
high with blowing
of 50-75 m p h , and
120 m p h ! The resulting
temperatures
southwest
in the 20's and
snow. Strong
Crested
Butte
s n o w f a l l , t h o u g h , was only
30's helped
to s t a b i l i z e
winds
the
that
recorded
a
peak
2-8" and
the new
snow
layer .
Another storm was right on its heels and moved into portions of the
San Juan M o u n t a i n s
Northern
and
in earnest
Purgatory
and Wolf Creek
Avalanche
Warning
after
on the night
terminating
got
was issued
the first
received
only
1 3 " , 1 7 " and
at 6:30
of the
17th. W h i l e
the
1-7", Red M o u n t a i n
22", respectively.
am on the
18th, only
Pass,
A second
four
days
one.
By the 19th, 20-40" of fresh snow had fallen in three days in
portions
42".
of the Southern M o u n t a i n s . Wolf Creek
The Warning
was cancelled
on the
24
led
these a m o u n t s
20th as the m o r n i n g
dawned
with
clear
and
very
cold
Colorado
counted
skier
-- Taylor
Park
recorded
on this m o r n i n g , a numbing
during
this p e r i o d , and
at Aspen H i g h l a n d s
the coldest
54 below
only
temperature
z e r o . Forty
one incident
that was partially
in
avalanches
was reported
were
-- a
buried.
Occasional light snow fell up to the 23rd which was not a problem
until
the
jet stream
northwest
Pass had
descended
winds with gusts
a gust
visibility
with
blowing
third
all areas
saw very
strong w i n d s
on
and
following
had
the a f t e r n o o n
(Purgatory
the Northern
avalanches
on the
produced
snow much of the t i m e , and
up to 9" by the 25th. The
howling
in excess of 60 m p h . M i n e s Peak at
Avalanche W a r n i n g
its c h a i r l i f t s ) , only
terminated
to provide
to 120 mph on the 23rd. The wind
January's
c l e a r e d . Twenty
over C o l o r a d o
Berthoud
zero
issuing
of the 23rd.
While
to close
day, temperatures
when
to
necessitated
ski area had
been recorded
west
received
rose and
the W a r n i n g
some
of
snow,
skies
was
26th.
On the 26th-29th, a major warmup brought temperatures in the 30' s
and
40's and
light w i n d s . The upper
dramatically. Temperatures
a v a l a n c h e s . The
but rather
were warm enough
significance
the long-term
snowpack
settled
and
to cause
stabilized
isolated
of this was not the s h o r t - t e r m
stability
that would
wet-snow
instability,
follow.
Another moist weather system passed through Colorado on the
3 0 t h - 3 1 s t . On each of those d a y s ,
Mountains;
2-6" of snow fell
3-10", in the Central M o u n t a i n s ; and
by light w i n d s , this storm
increase
hazard. About
two d a y s ,
but all were
released
did
20 slides were
by e x p l o s i v e s
Northern
2 - 4 " , in the
M o u n t a i n s . Accompanied
the a v a l a n c h e
in the
and
not
Southern
significantly
reported
for
these
no n a t u r a l e v e n t s
were
observed .
January was an active month for weather, avalanches, and
a c c i d e n t s . Almost
all areas got a b o v e - n o r m a l
1 8 8 % ; T e l l u r i d e , 1 3 5 % ; Winter
Gothic,
and
1 1 8 % ; Arapahoe
Sunlight,
managed
only
Basin and
1 1 2 % ; and
8 8 % , and
Park,
Berthoud
133%; Vail,
Aspen M o u n t a i n ,
Pass,
Breckenridge
25
snows: Monarch
accumulated
1 2 5 % ; Crested
1 1 5 % ; Copper
105%. Surprisingly
had 8 6 % . W a r n i n g s
were
Wolf
Butte
and
Mountain
Creek
issued
for
17
d a y s . The
caught
total number
in s l i d e s , and
of reported
a v a l a n c h e s was 6 9 3 , 10 people
3 people died. One vehicle was
were
destroyed.
But January also sowed the seeds of a stable snowpack for the
remainder
of the w i n t e r . Each storm was
which
the effect
had
And with
created
hoar
the warmup
of s t r e n g t h e n i n g
followed
the upper
by a w a r m i n g
layers
on the 2 6 t h - 2 9 t h , such a strong
in the upper half
of the snow cover
that
of the
layer
have
great difficulty
producing
deep-slab
snowpack.
had
been
it nullified
at the bottom. T h u s , for the rest of the w i n t e r , this
would
trend,
the
depth
snowpack
avalanches.
February
The mountain
storm
February
and
lst-3rd.
Some of the heavier
Vail,
brought
that
1 2 " ; Beaver
began on January
generous
Creek,
snows to all mountain
and Wolf
a r e a s on
a m o u n t s w e r e , in the N o r t h e r n
1 5 " ; Mary
J a n e , 2 3 " ; and
Central M o u n t a i n s , S n o w m a s s , 1 3 " ; Crested
S u n l i g h t , 2 2 " ; and
30th c o n t i n u e d
into
the
Mountains,
S t e a m b o a t , 2 3 " ; in
the
B u t t e , 1 5 " ; G o t h i c , 2 1 " ; and
in the Southern M o u n t a i n s , Red M o u n t a i n
Pass,
16";
Creek, 26".
These snows prompted an Avalanche Warning -- the sixth of the
season
-- which was issued
Thirty-five
and
avalanches
on the 3rd
were reported
in the only a v a l a n c h e
on the 3rd
early
on Wolf Creek
incident
terminated
to the Center
reported
Pass struck
and
on the
on the 3rd
and
in the m o n t h , a small
a c a r . No damage
or
4th.
4th;
slide
injuries
resulted .
A high-pressure ridge brought clear skies to the mountains on the
4 t h - 7 t h . A change came on the 8th when another
Northern
and
Central M o u n t a i n s , and
1 4 - 2 1 " in the Northern
while
Mountains
the Southern M o u n t a i n s
mph
on the
for
the Central
10th, and
snow
and
this prompted
and
reported
altogether. Winds
an A v a l a n c h e W a r n i n g
the Crested
in the warning
26
three
in the C e n t r a l
on the
areas during
the
days
gusted
on that
to
60
morning
area
11th. About
this
were
Mountains,
Butte-Gothic-Monarch
M o u n t a i n s . This W a r n i n g was dropped
a v a l a n c h e s were
system hit
totals the next
6-16"
got skipped
storm
episode.
60
of
The
ripped
of
12th and
through
13th were w a r m , clear
on the night
2 - 7 " to the Northern M o u n t a i n s
(except
1-2" to the Central
and
accompanied
p a s s a g e . Unsettled
continued
frontal
prevailed
of the
13th and
Steamboat
Southern M o u n t a i n s . Wind
in the Northern
fair weather
d a y s , but a v i g o r o u s
and
weather
gusts
with
in the Southern
got
cold
front
brought
snows
1 1 " ) but
of 60-85
snow
on the
only
mph
showers
14th-16th,
while
Mountains.
Clear skies on the 17th gave way to clouds and snow showers on the
1 8 t h - 2 0 t h . Another
21st with
cold
front
slammed
terrific w i n d s but almost
12,500 f e e t ) at Berthoud
on the night
no s n o w f a l l . M i n e s Peak
Pass recorded
three gusts
to
of
the
(elevation
120 mph
overnight.
A large ridge of high pressure developed on the 23rd and stayed in
place over Colorado
skies and
through
temperatures
the 2 7 t h . This brought
in the upper
30's to m i d - 4 0 ' s
preview
of spring. The ridge cracked
Pacific
moisture
flowed
clear,
slightly
on the
into the m o u n t a i n s and
—
a
bluebird
tantalizing
28th-29th
brought
as
snows of
1-4".
Monthly snowfalls showed wide variation, with the Northern
Mountains
getting
far more
than the Central and
f a c t , the Southern M o u n t a i n s
lst-3rd.
received
Snow t o t a l s , as a percent
M o u n t a i n s , Winter
113%; Vail,
virtually
all of its snow on
of n o r m a l , w e r e : in the
P a r k , 1 3 3 % ; Arapahoe
1 0 5 % ; Berthoud
Southern M o u n t a i n s . In
B a s i n , 1 2 4 % ; Copper
P a s s , 9 7 % ; and
the
Northern
Mountain,
B r e c k e n r i d g e , 8 4 % ; in
the
Central M o u n t a i n s , G o t h i c , 6 6 % ; M o n a r c h , 6 6 % ; Aspen M o u n t a i n , 6 1 % ; and
Crested
B u t t e , 5 4 % ; in the Southern M o u n t a i n s , Wolf C r e e k , 5 6 % ; and
Telluride, 51%.
The month's avalanche numbers reflect the low snowfall over twothirds of the mountain
below
n o r m a l . W a r n i n g s were only
backcountry
Wolf
a r e a . Only
Creek
avalanche
156 a v a l a n c h e s
effect
four
reported,
d a y s . T h e r e were
i n c i d e n t s w h a t s o e v e r , only
Pass mentioned
were
the minor
far
no
incident
on
earlier.
The weather of February had the effect of maintaining an overall
stable m o u n t a i n
s n o w p a c k , a stability
w a r m u p . All a v a l a n c h e s
during
initiated
the month were
27
Dy the
shallow
mid-January
slabs or
loose-snow
releases
resulting
strength
of the middle
the
from
fresh
loads of falling
snowpack
and
was sufficient
blowing
to prevent
snow.
The
avalanches
to
ground.
March
March weather
above-normal
C e n t r a l and
would
snowfalls
continue
the pattern
to the Northern M o u n t a i n s , w h i l e
Southern M o u n t a i n s w a n t i n g .
its driest March on
set in F e b r u a r y
and
leaving
bring
the
In f a c t , Wolf Creek would
record
record.
The first stormy period of the month had begun on February 28th and
continued
and
through
unorganized.
the first week
of M a r c h . This
S t i l l , there was good m o i s t u r e a v a i l a b l e
areas in the Northern M o u n t a i n s had
the 5th. The Central
for
and
1 8 - 1 9 " of new snow
this period, but there were
Mountain
storm was generally
averaged
and a few
by the m o r n i n g
3-6" of new
two e x c e p t i o n s : Gothic
weak
got
of
snow
1 7 " , and
Red
Pass, 16".
The next two days brought clear, bluebird skies to the Colorado
mountains
of
before
the next
storm appeared
the m o n t h , this pattern would
of stormy
by warm
weather
sunny
brought
be repeated
typical
v a r i e t y . Snowy
2 3 r d - 2 5 t h , and
time and
days of s n o w , only
s k i e s . These were
moving, hard-hitting
16th-17th,
2-3
on the 7th. For
spring
the
remainder
again as
to be replaced
storms of the
periods were
impulses
abruptly
fast-
the 7 t h - 8 t h ,
10th-13th,
28th-31st.
Accumulations of snow from these storms averaged 10-11" for the
Northern M o u n t a i n s , 7-8" for the Central M o u n t a i n s
Southern M o u n t a i n s . Wolf
per
storm
and
C r e e k , h o w e v e r , was only able
6-7"
for
the
to a v e r a g e
3.3"
this m o n t h .
Snow accumulations from the 3-day storm ending the 25th will help
illustrate
received
storm
the n o r t h - s o u t h
8-21" while
prompted
was issued
the Southern M o u n t a i n s
the only
A v a l a n c h e Warning
for the Northern M o u n t a i n s
the 26th. 25 slides were
eighth
and
bias this m o n t h : the N o r t h e r n M o u n t a i n
last of the
reported
season.
28
for
and
recorded
posted
began
only
a T - 2 " . This
for M a r c h . This
the 24th and
this warning
areas
ran
Warning
through
p e r i o d , which was
the
March
Northern
snow totals expressed
M o u n t a i n s , Berthoud
and Winter
as percent
Pass,
of normal
116%; Steamboat, 115%;
P a r k , 1 1 0 % ; Copper M o u n t a i n
and
Vail,
B u t t e , 6 1 % ; and
and
the
Breckenridge
1 0 4 % ; and
B a s i n , 8 8 % ; in the Central M o u n t a i n s , Aspen M o u n t a i n
M o n a r c h , 7 5 % ; and Crested
w e r e : in
Arapahoe
Gothic, 78%;
in the S o u t h e r n
Mountains,
T e l l u r i d e , 6 7 % ; and Wolf C r e e k , 2 1 % .
The backcountry snowpack generally became stronger as the month
p r o g r e s s e d , as warm
221 a v a l a n c h e s and
Six
temperatures
between
five a v a l a n c h e
storms helped
settle
i n c i d e n t s were recorded
people were c a u g h t , three were
partially
new
for
buried, but no
snows,
the month,
injuries
occurred.
April
As if on c u e , the last q u i c k - h i t t i n g
on the 3 1 s t , only
to leave
A p r i l . This warming
into
trend
the 4 0 ' s , until
through
winter's
more
b r i l l i a n t , sunny
c o n t i n u e d , with
of March
skies
for
temperature
during
the n i g h t . The morning
ended
highs
than 3" at any
30-40 m p h , it had
in the Central and
l o c a t i o n . Even
storm
little effect
slipped
of the 5th
found
with
the
Southern M o u n t a i n s measured
though
the storm
on the existing
packed
of
reaching
in the Northern M o u n t a i n s , but t r u e - t o - f o r m
trend, snow
abruptly
the b e g i n n i n g
late on the 4th when a fast-moving
3-8" of new snow
storm
winds
low a v a l a n c h e
no
of
hazard.
From the 6th-8th, temperatures returned to the 40's and 50's, and
spring was here to stay. Aside
typical
spring
relatively
arctic
mild
cold
storm near
the end
with no further
fronts for
from o c c a s i o n a l
snow
showers and a
of the m o n t h , the weather
threat
the remainder
of either
of the
severe
remained
blizzards
or
season.
During this same time, two things were happening in the snowpack.
F i r s t , upper
during
near
short-lived
avalanches
sunny
near the surface were gaining
the day. This was helped
temperatures
The
snow layers
that
the freezing
warmth
produced
released
a s p e c t s . Second,
heat
along with warm o v e r n i g h t
l e v e l , and
in s h a l l o w ,
from h i g h - e l e v a t i o n ,
29
was
low
in some c a s e s above
an increase
the snowpack
rapidly
steep
beginning
freezing.
wet-loose
terrain
to show
that
signs
had
of
becoming
isothermal
temperature
-- a spring-time
warms to the melting
condition
point
from
in which
the ground
the
snow
to the
surface.
A weak trough of low pressure moved into Colorado the night of the
8th and
continued
produced
through
the 9 t h . It was a familiar
up to 8" of snow
resulting
avalanche
left nothing
cool t e m p e r a t u r e s
activity
until
the
system
in the Northern M o u n t a i n s , gave a scant
to the Central M o u n t a i n s , and
The
story:
killed
in the S o u t h e r n
any
the next warming
possibility
trace
Mountains.
of continued
wet
trend.
High pressure took over once again on the 10th, and mostly fair
w e a t h e r , with
days.
some o c c a s i o n a l
A spring
moisture
storm, tracking
Temperatures
remained
sites confirmed
warm
light
during
that the snowpack
Pass study
for
the next
south of C o l o r a d o , then
in from the s o u t h w e s t . From
periods of snow showers and
Berthoud
c l o u d s , was the norm
the
pumping
1 5 t h - 2 0 t h , the m o u n t a i n s
snow that
provided
this p e r i o d , and
had
began
five
a T - 6 " of
reports
snow.
from
several
gone i s o t h e r m a l , including
plot at an elevation
above
11,200
saw
the
feet.
April 20th was to be the only nice day out of the next six. A
trough
of low pressure was deepening
projected
into
track was right
through
the area on the 2 1 s t , and
f a l l e n , this time with
Pass received
these
snow
the West Coast
its
by the next day, 5-11" of snow
fell intermittently
2 1 " , Red M o u n t a i n
until
with clear
had
the 2 6 t h , and
the s e a s o n ' s end.
Pass got 2 2 " , and Gothic
six d a y s . This was the last major
moved
in the N o r t h e r n , C e n t r a l , and
a surplus of snow before
month as April ended
and
the C o l o r a d o m o u n t a i n s . M o i s t u r e
equal d i s t r i b u t i o n s
Southern M o u n t a i n s . Light
some areas acquired
along
precipitation
skies and mild
Berthoud
logged
period
temperatures
of
3 3 " in
the
in the 4 0 ' s .
There were only 123 avalanches reported in April (100 less than
April
three;
1 9 8 7 ) , and
those carried
avalanche
skier
caught
the a v a l a n c h e hazard
a c c i d e n t s , none were
was caught
in their
damage);
a moderate
was rated
hazard
low every
rating. Although
s e r i o u s . On the 3rd, a
day
there were
a ski-tourer
on Red M o u n t a i n
was caught
30
near
Pass
(the car
Loveland
for
four
cross-country
in a slide near T e l l u r i d e ; on the 7 t h , two
vehicle
except
people
sustained
were
minor
Pass on the 9 t h ; and
on
the
16th, a ski patroller
avalanche
control
was caught
at Copper M o u n t a i n
while
doing
work.
Of the four observation sites that made daily reports for the
entire m o n t h , snowfall was slightly
Gothic
each
quiet
recorded
a v e r a g e , except
1 5 0 % of n o r m a l , while Winter
got 8 0 % , and
month
below
Berthoud
indeed, and
Pass had
relatively
31
Park and
8 3 % of normal
easy
for one
Arapahoe
area:
Basin
s n o w f a l l . April was a
on mountain
residents.
INFORMATION
ACQUISITION
Daily Weather, Snowpack, and Avalanche Data
The
Avalanche
assessments
Center
of current
and avalanche
hazard
data -- the C o l o r a d o
relies on
avalanche
incoming
stability,
data
and
to make
to m a k e m o u n t a i n
forecasts. There
are
two main
observer
and
the N a t i o n a l
network
accurate
sources
of
weather
these
Weather
Service.
Colorado observer network: The Center has established a network of
some 30 manned
observation
the sites are developed
report
current
sites
in the C o l o r a d o
ski a r e a s , from w h i c h
w e a t h e r , s n o w p a c k , and
sites are h i g h w a y , h e l i s k i , and
or contract
observers
report
observation
site will
be in place
valuable
data
from
snow-safety
avalanche
backcountry
m o u n t a i n s . Twenty
personnel
d a t a . The
remaining
s i t e s , from which
to the C e n t e r . One a d d i t i o n a l
for
the Elk M o u n t a i n s
the
1988-89
in c e n t r a l
of
season,
10
volunteers
backcountry
providing
Colorado.
A toll-free WATS line, linked to a Code-a-phone, is available for
the o b s e r v e r s ' c o n v e n i e n c e . T h i s gives q u a s i - 2 4 - h o u r
c a p a b i l i t i e s . O b s e r v e r s make m a n d a t o r y
updates during
forecaster
changeable
at the
morning
reporting
c a l l s , plus
c o n d i t i o n s . All data are
logged
timely
by
the
Center.
National Weather Service: Avalanche Center personnel have access to
all the products and
maps
(including
expertise
of the NWS
staff. Computerized
the p r o t o t y p e DARE w o r k - s t a t i o n ) ,
radar d a t a , r a d i o s o n d e
s t a t i o n s , and written
data, information
a n a l y s e s and
from manned
forecasts
are
A d d i t i o n a l l y , d i s c u s s i o n s with NWS f o r e c a s t e r s
products are an immense
help.
32
satellite
and
weather
photos,
remote
weather
available.
in i n t e r p r e t i n g
data
and
Westside Data Network
The C o l o r a d o
administration
portion
managing
of
weather
received
this computer
and
and
Computer
the Forest
from
a r e a s of
in Fort
for
the
Data N e t w o r k . A
Service
is earmarked
the C e n t e r
e v e n t , and
the United
for
serves
as
avalanche
S t a t e s . The
some 60 s i t e s in the m o u n t a i n
on m a g n e t i c
Center
is r e s p o n s i b l e
b a s e . In this c a p a c i t y ,
weather, avalanche
data
stored
Center
Service Westwide
from
for a v a l a n c h e - p r o n e
avalanche
computerized
University
data
for m o u n t a i n
data
Information
the U . S . Forest
the funding
a repository
accident
of
Avalanche
tape at the C o l o r a d o
West
are
State
Collins.
The Center also compiles Avalanche Notes, a monthly newsletter
which
contains
summaries
as well as a v a l a n c h e
monthly
of the c o m p u t e r i z e d
accident
from N o v e m b e r - A p r i l
people and
weather
and
avalanche
i n f o r m a t i o n . The n e w s l e t t e r
to 300 c o n t r i b u t o r s
and
other
is
data,
distributed
interested
agencies.
These data are used by Center personnel for keeping current on
present
conditions
in avalanche
and
during
accidents, relationships
d e p t h s , and
and
publications
for disseminating
this
10-20 requests a year
from
also
between
for later a n a l y s i s . T r e n d s '
survival
by Center
personnel
are
information. Additionally,
for
raw or tabulated
Service
lawyers.
33
and
information
the p u b l i c . L e c t u r e s , field
the ski i n d u s t r y , F o r e s t
r e s e a r c h e r s , and
and
types of r e s c u e s are e s s e n t i a l
on to snow s c i e n t i s t s
c o n t a c t s , and
the winter
burial
to be
times
passed
s e m i n a r s , media
some of the
the C e n t e r
responds
data. These requests
offices, universities,
methods
come
snow
to
DISSEMINATION
O F
H A Z A R D
F O R E C A S T S
The Colorado Avalanche Information Center provides avalanche and
mountain
weather
a u d i e n c e s . The
avalanche
information
following
hazard
to the p u b l i c , and
are
the o u t l e t s
used
to
specialized
by the Center
to
disperse
forecasts:
Public Hotlines
R e s i d e n t s in the
own avalanche h o t l i n e
public message
Forest
Southern M o u n t a i n
in place
p h o n e , located
S e r v i c e . The C e n t e r
that the public
conditions
can
call
more
are l o c a t i o n s
in D u r a n g o , w a s
for a current
hazard
than
this season. This r e p r e s e n t s
following
the first
now has seven
and an a v a l a n c h e
of this service as
for
and
r e g i o n were
time
provided
mountain
call-counts
systems
in
new
Colorado
forecast,
public made
placed
of 2 5 % over
for each
their
by the U . S .
weather
e v a l u a t i o n . The
29,380 calls were
to have
this w i n t e r . The
telephone
an increase
happy
to the
snow
good
use
hotlines
last y e a r !
The
phone:
Denver: Telephone messages are recorded twice daily on the U.S.
Forest Service
to this phone
increase
telephone
in L a k e w o o d . A total of
( 2 3 6 - 9 4 3 5 ) this winter
of 4% over
last
from
16,562 c a l l s were
the D e n v e r / B o u l d e r
made
a r e a , an
year.
Fort Collins: This message phone, sponsored by The Mountain Shop,
was back in operation
in November
to serve c a l l e r s along
Front R a n g e . The r e c o r d i n g
system
is housed
by the Larimer
and a d m i n i s t e r e d
2,835 calls were made
2 0 % over
last
is owned
the
by the A v a l a n c h e
County
to the 4 8 2 - 0 4 5 7 number
Sheriff's
northern
Center
Office.
and
Some
this w i n t e r , an increase
of
winter.
Colorado Springs: This is the third year of operation for this
p h o n e , and
call c o u n t s
continued
to i n c r e a s e . With more
to the 5 2 2 - 0 0 2 0 n u m b e r , the count went up by
with the Denver
twice daily
sponsored
and
Fort
Collins
s c h e d u l e , seven
by the A v a l a n c h e
Center and
34
3,100
last s e a s o n .
t e l e p h o n e s , u p d a t e s were m a d e
days a w e e k . T h i s
housed).
2 3 % over
than
system
the M o u n t a i n
is
calls
As
on a
jointly
Chalet
(where
it
is
Summit
pleasant
County:
surprise
J a n u a r y . The
replace
Dillon. Longer
located
when
Summit
the one
information
Residents
they
County
more
their
provided
dispensed
avalanche
with
the old
p h o n e , but
from
the end
of D e c e m b e r
hot
purchased
area
experienced
line
(668-0600)
a new
by the U . S . Forest
with
the new system
phone
than
A p r i l . The new phone
to
in
in this h i g h - u s e
more
in
local
c o u n t s w e r e not
recorded
a
system
Service
specific
to l i s t e n e r s
t e r r a i n . Call
through
County
local
complete messages
was now being
amidst much
called
Rescue Group
previously
and
in the Summit
area
available
2,850
calls
is housed
by
the
county .
Eagle County: The public message phone, housed and maintained by
the Forest
Service
in M i n t u r n
is not k n o w n . In a d d i t i o n
Patrols use daily
recorded
area
message
has no call
to this h o t l i n e , the Vail
information
phone
c o u n t e r , so the volume
from
-- a service
and
Beaver
of
use
Creek
the C e n t e r
to update
their
available
to skiers
leaving
Ski
own
the
ski
boundary.
Pitkin County: The Forest Service in Aspen maintains a public
message
phone
information
message
phone
for r e s i d e n t s
from
to their
and
t o u r i s t s . Forest
the C e n t e r ' s W A T S
line and
r e c o r d i n g . An estimated
personnel
transfer
1,260
an
get
daily
appropriate
c a l l s were m a d e
to
this
this w i n t e r .
Durango: The Avalanche Center, and local residents alike, were
pleased
to have a w e a t h e r
Impressive
enthusiasm
the tally
usage
avalanche
this w i n t e r . Since
count c o m p a r i s o n . But
Center watched
and
for
climb
the first
hotline
operating
in
this is a f i r s t , there
for the service
to 2,764 c a l l s
spread
by the end
the
is no
call
q u i c k l y , and
the
of A p r i l .
season!
Radio Broadcasts
We are pleased
communities airing
large listening
convey
our
to be finding
our
daily
audience
not
radio
stations
m e s s a g e s . T h i s has
previously
bulletins.
35
in v a r i o u s
given
r e a c h e d . The
mountain
us a c c e s s
following
to a
stations
For
its third
continued
s e a s o n , the
to record
and
public
broadcast
our
radio
station
daily
messages
season. Transmitting
on a main
translators
out on 8 8 . 9 , 8 9 . 1 , and
services
reaching
frequency
KVNF-FM
in
throughout
of 90.9 M H z , and
in s o u t h w e s t e r n
89.9 M H z , this
to a m e m o r i a l
fund
Colorado. Funding
for an a v a l a n c h e
victim
comes
killed
from
the
three
station
the towns of P a o n i a , M o n t r o s e , D e l t a , O u r a y , R i d g w a y ,
communities
Paonia
and
other
contributions
near Ridgway
in
1984.
Radio station KOTO in Telluride also broadcast our messages
throughout
the winter
recording
the m e s s a g e
avalanche
awareness
to r e s i d e n t s
in that a r e a . They
on the D u r a n g o
to an area
1 9 8 6 - 8 7 . There were no major
that
did
so by
h o t l i n e . This provided
had
accidents
four
deaths due
in that
region
increased
to a v a l a n c h e s
this
in
year.
In Summit County, K-Summit television and KSMT-FM radio continued
to support
weather
the C e n t e r ' s efforts
and
snowpack
talk-show
t i m e , and
televised
throughout
in reaching
i n f o r m a t i o n . They
taped
the
the public with
aired
timely
our m e s s a g e s , provided
i n t e r v i e w s with Center
personnel
that
live
were
county.
NOAA Colorado Weatherwire
When
the a v a l a n c h e
hazard
issue A v a l a n c h e W a r n i n g
is rated
b u l l e t i n s , twice
subsides and an A v a l a n c h e W a r n i n g
Special A v a l a n c h e
periods
A d v i s o r i e s may
into the higher
to the media
hazard
via the National
A, and T a b l e s
or e x t r e m e ,
d a i l y , until the
Termination
bulletin
is
forecasters
hazard
issued.
be sent out as well during
category. These
Oceanic
(NOAA) W e a t h e r w i r e . Sample w a r n i n g
Appendix
high
and
and
3 & 4 contain
bulletins are
Atmospheric
advisory
related
transition
transmitted
Administration
b u l l e t i n s are shown
in
information.
News Media
Forecasters
respond
to and
r a d i o , n e w s p a p e r , and m a g a z i n e
high
v i s i b i l i t y . T h e r e were
last
season. This
initiate
reporters
194 c o n t a c t s
is significant
because
fewer a c c i d e n t s , f a t a l i t i e s , w a r n i n g
year .
36
c o n t a c t s with
for
in
broad
news c o v e r a g e
1 9 8 7 - 8 8 , only
the winter
periods
television,
13 less
and
than
was less a c t i v e
and a v a l a n c h e s
—
than
-last
Media
avalanche
current
live and
personnel
frequently
w a r n i n g s , public
avalanche
taped
and
interest
mountain
interviews
called
were
for
information
stories, avalanche
weather
on
current
accidents,
c o n d i t i o n s . In a d d i t i o n ,
conducted
for radio
and
and
many
television
broadcasts.
About 20 inquiries came from outside Colorado including calls from
the New York T i m e s , Los A n g e l e s T i m e s , USA
T i m e s , U P I , Associated
and
National
Press, Baltimore
G e o g r a p h i c . A call
States this season came
Today, NBC, CBS,
S u n , KOBS-TV
to the Center
from Dutch
37
in F a r m i n g t o n ,
from o u t s i d e
International
Washington
the
Television.
NM,
United
PUBLIC
E D U C A T I O N
One of the main responsibilities of the Center is to provide
avalanche
education. Through
that accidents will
to the public
this
be kept
season
education
and
to a m i n i m u m .
through
three
public
a w a r e n e s s , we
The Center
provided
feel
education
outlets:
Avalanche Awareness Talks and Field Seminars
Avalanche
presentations
annual National
Avalanche
the last two talks were
began
as early
S c h o o l , held
given
on May
in Denver
9 t h , the
on 44 different
o c c a s i o n s , with a total
1-hour seminars
to 2-day
increase over
learn about
last
such
year
field
rescue
had
safe
travel
ski p a t r o l l e r s , search & rescue
in more
staff
had
spoken
attending
an
avalanche
astounding
ranged
to
terrain
t e c h n i q u e s , and
survival
from
volunteers,
Mountain Club m e m b e r s , ski c l u b s , and m e m b e r s
Table 8 lists these c o u r s e s
time
the o p p o r t u n i t y
t e c h n i q u e s . The s t u d e n t s ' b a c k g r o u n d s
professional
this y e a r . By the
represents
meteorology,
snowpack,
10th
Center
s e s s i o n s . This
topics as m o u n t a i n
1st at the
of 2,673 p e r s o n s
by 6 8 % ! P a r t i c i p a n t s
r e c o g n i t i o n , the C o l o r a d o
and
as N o v e m b e r
Colorado
of the g e n e r a l
public.
detail.
In order to monitor our efforts in providing avalanche awareness,
this season was the first
course
was:
time Center
p r e p a r a t i o n , driving
preparation
spent teaching
time and
- 36 h o u r s ; driving
the v a r i o u s
personnel
logged
presentation
the time
l e n g t h . The
time - 81 h o u r s ; and
spent
in
outcome
152
hours
courses.
ABC's Week
The Center was involved
known as A v a l a n c h e / B a c k
in a s t a t e w i d e
Country
Safety
1 1 - 1 8 . ABC'S Week was organized
and
Rescue Board
fatalities
designed
(CSRB),
of the 86-87
to r e a c h :
television
public
of 500,000 King
service
the phone numbers
of the
public
shopping
seven
was
the
( P S A ' s ) , and
bags which
11
Search
avalanche
first
of
its
in g e n e r a l , via radio
a special
presented
CAIC a v a l a n c h e
38
to the
program
January
Paul of the C o l o r a d o
in r e s p o n s e
announcements
awareness
(ABC'S W e e k ) on
s e a s o n . T h i s program
(1) the C o l o r a d o
Soopers
Week
by Howard
primarily
avalanche
hotlines
safety
kind
and
printing
tips
and
in C o l o r a d o ; and
Table 8.
Scheduled c o n t a c t s w i t h o r g a n i z e d
Center p e r s o n n e l , 1 9 8 7 - 8 8
groups
by
Avalanche
Attendance
Date
Personnel
Group
11/1-5
11/11
12/1
12/2
12/3
12/4
12/12-13
12/14
12/17
12/18
1/3
1/4-6
1/12
1/13
1/14
1/15
1/16
1/16
1/19
1/20
1/21
1/22
1/22
1/25-26
1/26
1/26
1/27
1/29
2/1
2/8-9
2/18-19
2/20
2/27
3/1
3/3
3/5
3/11
3/13
3/15
3/19-20
4/9
4/16
5/9
5/9
KW
N.
K.
K.
K.
N.
KW
K.
N.
N.
N.
N.
K.
D.
D.
A.
A.
N.
N.
K.
K.
D.
K.
N.
K.
K.
N.
D.
N.
N.
N.
N.
N.
K.
K.
N.
N.
D.
K.
K.
D.
D.
D.
N.
210
N a t i o n a l A v a l a n c h e S c h o o l , Denver
Public Awareness Talk, Breckenridge
125
North Face, Colorado Springs
60
North Face, Boulder
40
North F a c e , Denver
25
S u m m i t Teleraark S e r i e s , D u r a n g o
17
Summit Co. Rescue Group, Breckenridge
120
Public Awareness Course, Steamboat
100
Breckenridge Elementary School, Breck.
25
Summit Telemark Series, Leadville
18
B r e c k e n r i d g e S. A. e m p l o y e e s , B r e c k .
33
N a t i o n a l A v a l a n c h e S c h o o l , Copper M t n .
24
Mountain Shop, Ft. Collins
180
A v a l a n c h e A w a r e n e s s Week t a l k , Denver
300
A v a l a n c h e A w a r e n e s s Week t a l k , G o l d e n
300
S u m m i t T e l e m a r k S e r i e s , Aspen
4
P i t k i n C o . Public A w a r e n e s s , Aspen
150
N o r t h F a c e , Berthoud Pass
25
Public Awareness, Breckenridge
32
M o u n t a i n R e s c u e , Boulder
40
B e a v e r Creek Ski P a t r o l , Beaver Ck.
15
G r a y l a n d E l e m e n t a r y S c h o o l , Denver
65
Vail Ski P a t r o l , Vail
25
S u m m i t C o . P r o . A v a l . C o u r s e , Summit Co 18
Weathercasters Conference, Snowmass
25
S n o w m o b i l e C l u b , Glenwood
40
Mountain Chalet, Colorado Springs
65
Grand W e s t O u t f i t t e r s , C S / H o o s i e r Pass
42
W i n t e r Park N a t l . Ski P a t r o l , Denver
49
B r e c k e n r i d g e Ski P a t r o l , B r e c k e n r i d g e
6
B r e c k e n r i d g e Ski P a t r o l , B r e c k e n r i d g e
5
N S P S P a t c h C o u r s e , W i n t e r Park
14
Aspen Awareness, Snowmass
28
CSU c l a s s (Hal B o y n e ) , F t . C o l l i n s
12
C o l o . B l i z z a r d s S n o w m o b i l e Club
24
Summit Telemark Series, Breckenridge
40
Minturn Middle School, Minturn
58
N S P S I n s t r u c t o r s C l i n i c , Loveland S.A.
23
C o l o . M t n . Club M t n . S c h o o l , Boulder
80
N S P S Patch C o u r s e , Winter Park
14
N S P S Patch C o u r s e , Boulder
22
NSPS P a t c h C o u r s e , Loveland Ski Area
28
Evergreen Jr. High School, Evergreen
65
C o l o r a d o M o u n t a i n C l u b , Denver
82
& NL
Logan
Williams
Williams
Williams
Logan
, N L , A L , DA
Williams
Logan
Logan
Logan
Logan
Williams
Atkins
Atkins
Loving
Loving
Logan
Logan
Williams
Williams
Atkins
Williams
Logan
Williams
Williams
Logan
Atkins
Logan
Logan
Logan
Logan
Logan
Williams
Williams
Logan
Logan
Atkins
Williams
Williams
Atkins
Atkins
Atkins
Logan
TOTAL 2673
39
(2) the
backcountry
l e c t u r e s , slide
traveler
in p a r t i c u l a r , via a v a l a n c h e
p r o g r a m s , and
field
awareness
seminars.
Financial sponsors for ABC'S Week were Mountain Bell and KUSA-TV
(Channel
Rocky
active
9 in D e n v e r ) .
Mountain
Division
participants
for January
incidents
The A v a l a n c h e
of the N a t i o n a l
just
tragically
days prior
over
the
program
Service,
System
had
long
the season's only
served
been
two
and
as
scheduled
fatal
to ABC'S W e e k . H o w e v e r , b e c a u s e
these a c c i d e n t s , c o n s i d e r a b l e media
developed
Ski Patrol
in the program. The
l l t h - 1 8 t h , and
occurred
C e n t e r , U . S . Forest
attention
and
public
of
interest
program.
Knox Williams assisted the CSRB in developing the themes for the
public
service
announcements
accuracy
and
prepared
a written
by mountain
and
appropriateness
in format
basic avalanche
search and
rescue
1-1/2
hour avalanche
awareness
area,
the curriculum
was used
Atkins also was a speaker
audience
of almost
C o l l i n s , while
Aspen
in a three-day
awareness
after
ABC'S W e e k , all CAIC
course
program
in their
in programs
spent
just
forecasters
s h o w s , and
for
to present
a r e a . In the
reaching
for
Atkins
curriculum
rangers
over
use
a 1 to
Denver
1,000
people.
programs with a combined
spoke to almost
time
information
p r e s e n t a t i o n . Dale
forest
c o u r s e . Also
talk
and
at two evening
Loving
technical
teams and
600. Williams
Andy
i n t e r v i e w s , radio
provided
200 people an F t .
in Aspen assisting
prior
took
newspaper
t o , during
part
in
Mountain
and
Rescue
shortly
television
interviews.
The CSRB produced a media and materials kit consisting of three
separate
cassettes
skier
ago.)
1 5 , 2 0 , and
for use on local
Hank K a s h i w a .
KUSA-TV
Also included
for
local
aired
the PSA's
were eight
30-second
from January
radio PSA's
and
of a USFS
series of posters
by KUSA-TV
for
4th
local
feature
stations
video
was
many
to the end
educational
newspaper
on
spokesman
in a large a v a l a n c h e
reproduction-ready
a reproduction-ready
a copy
produced
cable TV. The on-air
(He was caught
A v a l a n c h e : How to avoid
included
PSA's,
print m e d i a , six p r e - w r i t t e n
pre-written
live, and
30-second
Olympic
years
of
and
February.
safety
stories,
to record
copy
of the USFS brochure
"Snow
survive
avalanches". Lastly,
the
17-minute
to be displayed
40
avalanche
awareness
in s t o r e s , r e s t a u r a n t s
or
eight
air
kit
video and
and
ads
a
trailheads
promoting
and
ABC'S W e e k . T h e s e
rescue
teams and
the s t a t e . T h e s e
avalanche
kits w e r e
8 selected
organizations
awareness
programs
distributed
Forest
were
Service
encouraged
to people
to 36 m o u n t a i n
Ranger
Districts
to p r e s e n t
in their
local
search
across
their
own
areas.
Just prior to the start of ABC'S Week, a media seminar was held in
Denver
key
to formally
contacts
incidents.
the major
and
introduce
channels
A B C ' S Week
for o b t a i n i n g
It was well a t t e n d e d
network
representative
by
a f f i l i a t e s . The
from
the C o l o r a d o
and
to present
information
the local
program
on
Denver
with
avalanche
media
was hosted
Sheriff's
the m e d i a
as well
as
by the CSRB with
Association
and
Atkins
a
from
the CAIC as s p e a k e r s .
The Center was very pleased with ABC'S Week. The Colorado Search
and Rescue
audience
the end
Board
is in the
reached
of e v a l u a t i n g
so as to d e t e r m i n e
of April
thanking
process
the CSRB received
the CSRB and
its impact
a letter
the p a r t i c i p a t i n g
the size of
and
the
effectiveness.
from G o v e r n o r
a g e n c i e s and
Roy
Near
Romer
organizations
for
ABC'S W e e k .
Avalanche Cards and Brochures
Printed
material
in the
brochures
is distributed
in return
letters
all of the public
hazard
form of w a l l e t - s i z e
at all l e c t u r e s and
of c o r r e s p o n d e n c e
hotline
where they
and
the
p h o n e n u m b e r s and
r a t i n g s . The b r o c h u r e s
information
with
carry
to avoid
cards
s e m i n a r s , and
is
p u b l i c . The cards
a definition
contain
of the
-- how to r e c o g n i z e
and
included
this i n f o r m a t i o n , as well as
diagrams a b o u t a v a l a n c h e s
o c c u r , and how
avalanche
four
basic
areas
them.
The Summit County Rescue Group printed special cards similar in
nature but designed
conjunction
Their
with
personnel
in Summit
County
specifically
the new p h o n e
distributed
which
for
system
and
the Summit
installed
maintained
generated
41
much
County
a r e a . T h i s was
in this area
avalanche
use of the new
in
poster/card
phone.
in
January.
holders
H A Z A R D
G R A D I N G
For the fourth year, the Avalanche Center has used a grading system
for evaluating
its p e r f o r m a n c e
focuses
"avalanche
on the
snowpack
d a t a . To arrive
evaluation
Southern
for the next
"Daily
24-hour
period
is based
on
Information
c a t e g o r i e s . On the
following
the o b s e r v e r s ' e s t i m a t e s
"correct
then entered
onto
and
prediction
makes
and
an
the N o r t h e r n , C e n t r a l ,
data
the
of c u r r e n t
forecast
C h a r t " using
-- is c o m p a r e d
This
weather
forecaster
d a y , the a c t u a l
f o r e c a s t " , "under
the
the
field
Decision
forecasting.
on incoming
for
p r e d i c t i o n . Each a f t e r n o o n
Hazard
A grade of
p o t e n t i a l " based
at a f o r e c a s t ,
M o u n t a i n s . This
the weather
of a v a l a n c h e
hazard
stability
is logged
in
one of the
rating
to the p r e v i o u s
—
and
the
four
based
day's
f o r e c a s t " , or "over
and
on
forecast.
forecast"
is
chart.
Avalanche hazard forecasts are expressed by using the terms "low",
" m o d e r a t e " , " h i g h " or " e x t r e m e " to d e p i c t
the hazard
This has been slightly
season. Forecasters
had
the freedom
hazard
modified
to combine
rating. It was
from
two of these
felt that
terms
by doing
too general a f o r e c a s t . This season
one of the four
last
terms to d e s c r i b e
each
the
in a given
area.
previously
to d e s c r i b e
the
current
s o , the listener
was
getting
forecaster
choose
could
only
hazard.
The scores for this and previous years are shown in the following
table:
Correct
Over
1987-88
1986-87
1985-86
1984-85
86%
95%
92%
81%
8%
2%
5%
12%
6%
3%
3%
11
forecast
forecast
Under
forecast
We are still satisfied with the results, for two reasons. First,
the " c o r r e c t " forecast
field
that
accuracy
is as much
figures
still exceeds
is m a i n t a i n i n g
art as s c i e n c e . We will
greater
than 8 0 % . S e c o n d ,
" u n d e r " f o r e c a s t s . It
of o v e r e s t i m a t i n g
an a c c e p t a b l e
the danger
rather
42
is m o r e
than
the
percentage
remain
pleased
with
"over" forecast
desirable
to err
underestimating.
in a
rate
on the
side
S A M P L E
A V A L A N C H E
W A R N I N G S
A N D
ADVISORIES
This section shows examples of products that Avalanche Center
forecasters
Avalanche
issued
Warning
via the NOAA
Bulletins
an example
of a Special
a four-day
avalanche
bulletins
selected
the
at
Weatherwire. This
a Special
Avalanche
warning
from
and
Colorado
Avalanche
Advisory;
the end
43
Advisory.
pages 4 5 - 4 8
of J a n u a r y , and
longest-running
season.
while
includes
warning
Page
of
is
represent
pages 49-52
period
44
the
are
TTAAOO KDEN 092245
SPECIAL A V A L A N C H E ADVISORY
C O L O R A D O A V A L A N C H E I N F O R M A T I O N CENTER
N A T I O N A L WEATHER SERVICE DENVER CO
3:45 PM TUESDAY FEBRUARY 9, 1988
...NORTHERN AND CENTRAL COLORADO MOUNTAINS...BACKCOUNTRY AVALANCHE
HAZARD I N C R E A S I N G . . .
THE AVALANCHE PUBLIC MESSAGE TELEPHONE FOR THE DENVER/BOULDER AREA IS
T E M P O R A R I L Y OUT OF S E R V I C E . WE ASK THAT YOU PASS ALONG THIS A V A L A N C H E
ADVISORY ... UNTIL OUR PHONE IS BACK IN SERVICE IN A DAY OR T W O .
THE BACKCOUNTRY AVALANCHE HAZARD IN THE NORTHERN MOUNTAINS OF COLORADO
IS C U R R E N T L Y RATED M O D E R A T E WITH P O C K E T S OF L O C A L I Z E D HIGH H A Z A R D A B O V E
T I M B E R L I N E . IN THE CENTRAL M O U N T A I N S IT IS RATED M O D E R A T E . SNOW AND W I N D
T O N I G H T COULD INCREASE THE HAZARD ABOVE T I M B E R L I N E IN THE N O R T H E R N AND
CENTRAL M O U N T A I N S TO ... HIGH O V E R A L L .
A MODERATE HAZARD MEANS THAT NATURAL AVALANCHE RELEASES ARE
U N L I K E L Y . . . B U T AREAS OF U N S T A B L E SNOW EXIST AND SKI OR
T R I G G E R E D RELEASES ARE P O S S I B L E ON STEEPER S L O P E S .
SNOWMOBILE
A HIGH HAZARD MEANS THAT BOTH NATURAL AND TRIGGERED AVALANCHE RELEASES
ARE LIKELY IN STEEPER A R E A S . WE R E C O M M E N D THAT B A C K C O U N T R Y SKIERS AND
S N O W M O B I L E R S AVOID STEEPER TERRAIN AND LIMIT TRAVEL TO G E N T L E T E R R A I N
AND M A I N T A I N E D T R A I L S .
THIS STATEMENT IS OF PARTICULAR INTEREST TO PERSONS USING THE
B A C K C O U N T R Y OUTSIDE OF DEVELOPED SKI AREA B O U N D A R I E S . W H E R E N E C E S S A R Y ,
SKI AREAS USE A V A L A N C H E CONTROL M E T H O D S WITHIN THEIR B O U N D A R I E S .
FOR ADDITIONAL AVALANCHE INFORMATION CALL ... 236-9435 IN DENVER AND
BOULDER ... 482-0457 IN F T . COLLINS ... 520-0020 IN C O L O R A D O
6 6 8 - 0 6 0 0 IN SUMMIT COUNTY ... AND 247-8187 IN D U R A N G O .
WILLIAMS
COLORADO
8788
AVALANCHE
INFORMATION
CENTER
44
SPRINGS
...
TTAAOO KDEN 240007
A V A L A N C H E WARNING BULLETIN NO 1
N A T I O N A L WEATHER S E R V I C E DENVER CO
5:00 PM SATURDAY JANUARY 2 3 , 1988
...AVALANCHE WARNING FOR NORTH AND CENTRAL COLORADO MOUNTAINS...
AN AVALANCHE WARNING IS IN EFFECT IMMEDIATELY FOR ALL MOUNTAIN AREAS
NORTH OF A LINE FROM PUEBLO TO M O N T R O S E . THIS W A R N I N G IS IN E F F E C T
THROUGH SUNDAY JANUARY 2 4 . NEW SNOW OF 3 TO 6 INCHES IN THE C E N T R A L
M O U N T A I N S , AND HIGH W I N D S OF 30 TO 50 MPH IS T R A N S P O R T I N G THIS NEW SNOW
INTO A V A L A N C H E STARTING Z O N E S .
THE AVALANCHE HAZARD FOR ALL COLORADO MOUNTAINS AT AND ABOVE TREELINE
IS RATED H I G H . BELOW T R E E L I N E THE HAZARD IS RATED M O D E R A T E W I T H AREAS
OF HIGH HAZARD ESPECIALLY ON SLOPES FACING SOUTH TO E A S T . T R I G G E R E D
A V A L A N C H E R E L E A S E S BY A SKIER OR SNOWMOBILER ARE LIKELY IN T H E S E A R E A S
OF HIGH H A Z A R D . WE RECOMMEND THAT B A C K C O U N T R Y T R A V E L L E R S AVOID ALL
STEEP SNOWLOADED SLOPES OF 30 DEGREES AND STEEPER NEAR AND ABOVE
TREELINE.
BOULDER ... 482-0457 IN F T . C O L L I N S ... 520-0020 IN C O L O R A D O
... 6 6 8 - 0 6 0 0 IN SUMMIT COUNTY ... AND 247-8187 IN D U R A N G O .
ATKINS
COLORADO AVALANCHE
8788/5-1
INFORMATION
CENTER
45
SPRINGS
TTAAOO KDEN 242318
A V A L A N C H E W A R N I N G BULLETIN NO 2
N A T I O N A L WEATHER SERVICE DENVER CO
4:20 PM .SUNDAY JANUARY 2 4 , 1988
...NORTH AND CENTRAL MOUNTAINS... AVALANCHE HAZARD HIGH...
AN AVALANCHE WARNING REMAINS IN EFFECT FOR ALL MOUNTAIN AREAS OF
C O L O R A D O NORTH OF A LINE FORM PUEBLO TO M O N T R O S E . THIS W A R N I N G W I L L
REMAIN VALID THROUGH MONDAY JANUARY 2 5 . SNOWFALL OF 3 TO 7 INCHES OF
SNOW LAST N I G H T WITH A D D I T I O N A L SNOW EXPECTED T O N I G H T IN THE NORTH AND
CENTRAL M O U N T A I N S A C C O M P A N I E D BY STRONG WINDS OF 30 TO 50 MPH W I L L
C O N T I N U E TO LOAD A V A L A N C H E STARTING ZONES NEAR AND ABOVE T R E E L I N E .
THE AVALANCHE HAZARD FOR ALL COLORADO MOUNTAINS AT AND ABOVE TREELINE
IS RATED H I G H . BELOW T R E E L I N E THE HAZARD IS RATED M O D E R A T E WITH A R E A S
OF HIGH HAZARD ESPECIALLY IN SLOPES FACING SOUTH TO N O R T H E A S T .
T R I G G E R E D A V A L A N C H E R E L E A S E S BY A SKIER OR SNOWMOBILER ARE LIKELY IN
THESE AREAS OF HIGH H A Z A R D . WE R E C O M M E N D THAT B A C K C O U N T R Y T R A V E L L E R S
AVOID ALL STEEP S N O W L O A D E D SLOPES OF 30 D E G R E E S AND STEEPER NEAR AND
ABOVE T R E E L I N E .
BOULDER ... 482-0457 IN F T . COLLINS ... 520-0020 IN C O L O R A D O
ATKINS
COLORADO
8788/5-2
AVALANCHE
INFORMATION
CENTER
46
SPRINGS
TTAAOO KDEN 251811
A V A L A N C H E W A R N I N G BULLETIN NO 3
11:15 AM MONDAY JANUARY 2 5 , 1988
...NORTH AND CENTRAL MOUNTAINS...AVALANCHE WARNING EXTENDED...
THE AVALANCHE WARNING HAS BEEN EXTENDED FOR THE NORTHERN AND CENTRAL
MOUNTAIN AREAS OF C O L O R A D O . NEW SNOWS F O R E C A S T FOR THE N O R T H E R N AND
C E N T R A L M O U N T A I N S LAST NIGHT DID NOT ARRIVE AND A V A L A N C H E H A Z A R D S ARE
NOT BUILDING AS QUICKLY AS E X P E C T E D . S T I L L , STRONG N O R T H W E S T W I N D S OF
30 TO 50 MPH W I L L C O N T I N U E TO LOAD A V A L A N C H E STARTING Z O N E S T O D A Y .
THE AVALANCHE HAZARD FOR ALL COLORADO MOUNTAINS IS RATED HIGH AT AND
ABOVE T R E E L I N E . BELOW T R E E L I N E THE HAZARD IS RATED M O D E R A T E . W I T H
STRONG W I N D S T O D A Y , A V A L A N C H E H A Z A R D S WILL C O N T I N U E TO B U I L D IN T H E
STEEP STARTING ZONES L O C A T E D BOTH ABOVE AND BELOW T R E E L I N E . THE
A V A L A N C H E HAZARD IN T H E S E STEEP S N O W L O A D E D AREAS BELOW T I M B E R L I N E IS
RATED H I G H , E S P E C I A L L Y ON SLOPES FACING SOUTH TO N O R T H E A S T . T R I G G E R E D
A V A L A N C H E R E L E A S E S BY A SKIER OR SNOWMOBILER ARE LIKELY IN ALL A R E A S OF
HIGH A V A L A N C H E H A Z A R D . B A C K C O U N T R Y V I S I T O R S SHOULD AVOID ALL S T E E P
SNOWLOADED SLOPES AND G U L L I E S W H I C H ARE 30 D E G R E E S AND S T E E P E R . SAFER
SKIING MAY BE FOUND IN THE GENTLE TERRAIN WELL AWAY FROM STEEP
A V A L A N C H E PRONE A R E A S .
B A C K C O U N T R Y OUTSIDE OF D E V E L O P E D SKI AREA B O U N D A R I E S . W H E R E N E C E S S A R Y ,
LOVING
COLORADO AVALANCHE
8788/5-3
INFORMATION
CENTER
47
SPRINGS
TTAAOO KDEN 261557
A V A L A N C H E WARNING T E R M I N A T I O N
9:00 AM TUESDAY JANUARY 2 6 , 1988
...NORTH AND CENTRAL MOUNTAINS...AVALANCHE WARNING TERMINATED...
THE AVALANCHE WARNING HAS BEEN TERMINATED FOR THE NORTHERN AND CENTRAL
M O U N T A I N AREAS OF C O L O R A D O .
THE AVALANCHE HAZARD FOR ALL COLORADO MOUNTAINS IS RATED HIGH AT AND
ABOVE T R E E L I N E . BELOW T R E E L I N E THE HAZARD IS RATED M O D E R A T E . W I N D B L O W N
SNOW HAS A C C U M U L A T E D ON STEEP SLOPES AND G U L L I E S L O C A T E D BELOW
T R E E L I N E . THE AVALANCHE HAZARD IN THESE STEEP S N O W L O A D E D P O C K E T S BELOW
T I M B E R L I N E IS ALSO RATED H I G H . THIS IS E S P E C I A L L Y TRUE FOR SLOPES W I T H
N O R T H E A S T T H R O U G H SOUTH A S P E C T S . T R I G G E R E D A V A L A N C H E R E L E A S E S BY A
SKIER OR SNOWMOBILER ARE LIKELY IN ALL AREAS OF HIGH A V A L A N C H E H A Z A R D .
B A C K C O U N T R Y V I S I T O R S SHOULD AVOID ALL STEEP S N O W L O A D E D SLOPES W H I C H ARE
30 D E G R E E S AND STEEPER.
B A C K C O U N T R Y OUTSIDE OF D E V E L O P E D SKI AREA B O U N D A R I E S . W H E R E N E C E S S A R Y ,
BOULDER ... 482-0457 IN F T . COLLINS ... 5 2 0 - 0 0 2 0 IN C O L O R A D O
LOVING
COLORADO AVALANCHE
8788/5-4
INFORMATION
CENTER
48
SPRINGS
TTAAOO KDEN 051722
A V A L A N C H E WARNING BULLETIN N O . 1
NATIONAL WEATHER S E R V I C E DENVER CO
10:30 AM MST TUESDAY JANUARY 5, 1988
...AVALANCHE HAZARD HIGH ABOVE TIMBERLINE ALL COLORADO MOUNTAINS...
AN AVALANCHE WARNING IS IN EFFECT IMMEDIATELY AT AND ABOVE TIMBERLINE
FOR B A C K C O U N T R Y AREAS OF ALL C O L O R A D O M O U N T A I N S . THE C A U S E S OF THE HIGH
B A C K C O U N T R Y A V A L A N C H E HAZARD ARE O V E R N I G H T S N O W F A L L S OF 4-14 I N C H E S AND
WINDS ABOVE T I M B E R L I N E OF 20-40 M P H .
THIS WARNING IS VALID THROUGH WEDNESDAY MORNING.
POOR VISIBILITY IS HAMPERING BACKCOUNTRY AVALANCHE OBSERVATIONS ... BUT
THUS FAR SLIDES HAVE BEEN R E P O R T E D AT T E L L U R I D E AND RED MTN PASS IN THE
SOUTHERN M O U N T A I N S ... AND AROUND GOTHIC IN THE C E N T R A L M O U N T A I N S . M O R E
A V A L A N C H E ARE E X P E C T E D AS MOUNTAIN SNOWS ARE E X P E C T E D TO C O N T I N U E .
WE RECOMMEND THAT BACKCOUNTRY SKIERS AND SNOWMOBILERS LIMIT TRAVEL TO
GENTLE TERRAIN ... FOR NATURAL AND T R I G G E R E D A V A L A N C H E S ARE LIKELY ON
SLOPES EXCEEDING 30 D E G R E E S S T E E P N E S S . IT IS A GOOD TIME TO SKI AT A SKI
AREA.
THIS BULLETIN IS OF PARTICULAR INTEREST TO PERSONS USING THE
BACKCOUNTRY OUTSIDE OF DEVELOPED SKI AREA B O U N D A R I E S . W H E R E N E C E S S A R Y ,
BOULDER ... 482-0457 IN F T . COLLINS ... AND 520-0020 IN C O L O R A D O
SPRINGS.
THE NEXT AVALANCHE BULLETIN IS SCHEDULED FOR 4 PM TODAY.
WILLIAMS
COLORADO
8788/3-1
AVALANCHE
INFORMATION
CENTER
49
TTAAOO KDEN 092145
A V A L A N C H E WARNING BULLETIN N O . 10
NATIONAL WEATHER S E R V I C E DENVER CO
2:45 PM MST SATURDAY JANUARY 9, 1988
AVALANCHE WARNING EXTENDED TO SUNDAY...ALL COLORADO MOUNTAIN AREAS
AN AVALANCHE WARNING REMAINS IN EFFECT FOR ALL BACKCOUNTRY AREAS OF THE
COLORADO M O U N T A I N S . THE A V A L A N C H E HAZARD FOR THE N O R T H E R N , C E N T R A L
SOUTHERN M O U N T A I N S REMAINS HIGH BOTH ABOVE AND BELOW T I M B E R L I N E .
AND
APPROXIMATELY 25 AVALANCHES, BOTH NATURAL AND TRIGGERED, HAVE BEEN
REPORTED TO THE CENTER T O D A Y . T H E S E SLIDES HAVE G E N E R A L L Y BEEN C O N F I N E D
TO THE NEW SNOW WHICH HAS BEEN MOVED TO LEE SLOPES AND G U L L I E S BY R E C E N T
STRONG W I N D S ABOVE T I M B E R L I N E . ONE NATURAL SLIDE ON B E R T H O U D PASS C A U G H T
AND DAMAGED AN A U T O M O B I L E THIS M O R N I N G . THE SINGLE O C C U P A N T OF THE CAR
WAS NOT I N J U R E D . HIGHWAY 40 WAS CLOSED FOR A P P R O X I M A T E L Y FOUR H O U R S .
NATURAL AND TRIGGERED AVALANCHES ARE LIKELY IN THE AREAS OF THE
COLORADO BACKCOUNTRY WITH A HIGH A V A L A N C H E H A Z A R D . T H O U G H N A T U R A L
RELEASES ARE LESS LIKELY IN AREAS WITH A M O D E R A T E H A Z A R D , T R I G G E R E D
R E L E A S E S REMAIN P O S S I B L E IN STEEP S N O W L O A D E D SLOPES OF THIRTY D E G R E E S
S T E E P E R , FACING NORTH THROUGH S O U T H - E A S T .
BACKCOUNTRY SKIERS AND SNOWMOBILERS SHOULD CONTINUE TO AVOID STEEP
S N O W L O A D E D SLOPES AND G U L L I E S . SAFE SKIING IS A V A I L A B L E IN THE
TERRAIN WELL AWAY FROM A V A L A N C H E PRONE A R E A S , THOUGH WE DO NOT
TRAVEL IN THE BACKCOUNTRY AT A L L , TODAY OR T O M O R R O W .
GENTLE
RECOMMEND
SKI AREAS USE AVALANCHE CONTROL M E T H O D S WITHIN THEIR B O U N D A R I E S .
... AND 247-8187 IN D U R A N G O .
THE NEXT AVALANCHE BULLETIN IS SCHEDULED FOR 11 AM SUNDAY.
LOVING
COLORADO A V A L A N C H E
8788/3-10
INFORMATION
CENTER
50
OR
SPRINGS
TTAAOO KDEN 102311
A V A L A N C H E WARNING B U L L E T I N N O . 12
N A T I O N A L W E A T H E R SERVICE DENVER CO
4:00 PM MST SUNDAY JANUARY 1 0 , 1988
...AVALANCHE WARNING EXTENDED IN ALL COLORADO MOUNTAINS...
AN AVALANCHE WARNING REMAINS IN EFFECT FOR ALL BACKCOUNTRY AREAS OF THE
C O L O R A D O M O U N T A I N S . THE A V A L A N C H E H A Z A R D IS RATED H I G H BOTH A B O V E AND
BELOW T R E E L I N E . THIS W A R N I N G WILL REMAIN IN E F F E C T T H R O U G H M O N D A Y .
THREE BACKCOUNTRY SKIERS IN THE CENTRAL MOUNTAINS NEAR ASHCROFT HAVE
BEEN R E P O R T E D BURIED IN AN A V A L A N C H E TODAY AND A SEARCH IS
THIS A F T E R N O O N .
UNDERWAY
NATURAL AND TRIGGERED AVALANCHES ARE LIKELY AT THIS TIME. BACKCOUNTRY
SKIERS AND S N O W M O B I L E R S ARE URGED TO AVOID STEEP S N O W L O A D E D S L O P E S
GULLIES AND STAY W E L L AWAY FROM STEEP OPEN SLOPES A B O V E Y O U .
AND
... AND 247-8187 IN D U R A N G O .
THE NEXT AVALANCHE BULLETIN IS SCHEDULED FOR MONDAY MORNING
LOGAN
COLORADO AVALANCHE
8788/3-12
INFORMATION
CENTER
51
SPRINGS
TTAAOO KDEN 142332
A V A L A N C H E T E R M I N A T I O N BULLETIN NO. 17
N A T I O N A L W E A T H E R S E R V I C E DENVER CO
4:15 PM MST T H U R S D A Y J A N U A R Y 1 4 , 1988
...ALL COLORADO MOUNTAINS ... AVALANCHE HAZARD EASING...
THE AVALANCHE WARNING FOR THE COLORADO MOUNTAINS HAS BEEN CANCELLED.
LITTLE A D D I T I O N A L S N O W F A L L , LIGHTER W I N D S , AND WARMER T E M P E R A T U R E S ARE
HELPING EASE THE H A Z A R D . H O W E V E R , THE A V A L A N C H E H A Z A R D IS STILL R A T E D
HIGH FOR ALL AREAS AT AND ABOVE T R E E L I N E . BELOW T R E E L I N E , THE H A Z A R D ON
SLOPES FACING NORTH TO S O U T H E A S T IS STILL H I G H . ON SLOPES FACING SOUTH
TO W E S T TO NORTH BELOW T R E E L I N E , THE HAZARD IS M O D E R A T E .
OVER 520 AVALANCHES WERE REPORTED DURING THE WARNING PERIOD. AVALANCHES
T R I G G E R E D BY A B A C K C O U N T R Y SKIER OR S N O W M O B I L E ARE STILL LIKELY IN T H E
AREAS OF HIGH H A Z A R D , IN AREAS OF M O D E R A T E H A Z A R D , T R I G G E R E D R E L E A S E S
ARE P O S S I B L E . B A C K C O U N T R Y T R A V E L L E R S ARE ADVISED TO AVOID S T E E P ,
S N O W L O A D E D S L O P E S , EVEN THOSE BELOW T R E E L I N E . . . AND AVOID STEEP OPEN
SLOPES FROM A B O V E .
B A C K C O U N T R Y O U T S I D E OF D E V E L O P E D SKI AREA B O U N D A R I E S . W H E R E N E C E S S A R Y ,
SKI AREAS USE AVALANCHE CONTROL M E T H O D S WITHIN THEIR B O U N D A R I E S .
... AND 247-8187 IN D U R A N G O .
ATKINS
COLORADO AVALANCHE INFORMATION
8788/3-17
CENTER
52
SPRINGS
L E T T E R S A N D
N E W S P A P E R
ARTICLES
This appendix includes several letters commenting on the service
provided
which
by
helped
the A v a l a n c h e
the Center
Center
get
and
a sampling
its i n f o r m a t i o n
53
of n e w s p a p e r
to the
public.
stories
A
N
D E A N
O U T F I T T E R
Outfitters & G u i d e s for S o u t h A m e r i c a
2 2 / April
Avalanche Hazard
Denver
HVi
^enter
Oo::t I d m e n :
J'tgt want to say I r;all.y apoi'iiclate your w' iter storm
jiiid avui anohe f o r o c a s t n .
'/e, out h e r e , spend about six
Months a y e a r wlththe s n o w p a c k , and your service Is
deenly a p p r e c i a t e d .
j-'our v/eal.hor forecasts, an board on "adlo KOTO, Telluride,
are the bo:;t they h a v e had '.n the 9 y e a r n I've- b e e n
listening.
Glad to (j,e t theiri -- wish you could k e e p
un all. y e a r .
'ihank3.
Jack
Miller
P. O. BOX 220 - RIDGWAY, COLORADO 81432 - (303) 626 - 5918
It
S
COLORADO DEPARTMENT OF NATURAL RESOURCES
COLORADO AVALANCHE INFORMATION CENTER
10230 SMITH ROAD
DENVER, COLORADO 8 0239
MAY 12, 1988
DEAR FOLKS,
WE WOULD LIKE TO EXPRESS OUR SINCERE APPRECIATION
FOR THE FINE SERVICE THE COLORADO AVALANCHE INFORMATION
CENTER PROVIDED THIS PAST WINTER. WE UTILIZED THE DURANGO
BRANCH OF YOUR SERVICE ON A DAILY BASIS, AND IT BECAME AN
INTEGRAL PART OF OUR NEWS AND WEATHER DEPARTMENT.
AS YOU KNOW, WEATHER AND AVALANCHE CONDITIONS FOR
AN AREA AS LARGE AND AS VARIED AS COLORADO CAN BECOME
RATHER VAGUE, BUT YOUR REPORTS WERE SOMEWHAT PERSONALIZED
WHEN 'TELLURIDE' AND 'THE SAN JUANS' WERE SPECIFICALLY
MENTIONED. IT WAS A FAVORITE WITH OUR LISTENERS.
THANKS VERY MUCH FOR THE SERVICE AND WE HOPE THAT
YOU CAN CONTINUE YOUR REPORTS NEXT WINTER*
WE LOOK FORWARD
TO IT.
SINCERELY,
^ i ^ j h s u y
BEN KERR
PROGRAM DIRECTOR
KOTO-FM
9 1 . 7
F
M
C
O
M
M
U
N
I
T
Y
R A D I O
I N
T E L L U R I D E
T H E S A N M I G U E L E D U C A T I O N A L F U N D . B O X 1069 • T E L L U R I D E , C O 8 1 4 3 5 • 728-4333/4
jim bcdford
box 601
540 h. galena ,ive.
telluride, co 8I4J5
Colorado Avalanche Information Center
10230 Smith Road
Denver, C O
80239
419.88
Dear Avalanche Folks:
Thanks for another great season! Your continued clear and area specific
reporting adds to the safety and welfare of all citizens and visitors to
the mountains of Colorado.
Our local radio station, KOTO-fm, has broadcast reports all season from
your service. Last year, four back-country skiers were killed by
avalanches in this area. This year, there were no deaths, and only a few
small incidents which caused no bodily harm. I really believe that if
this service is expanded, and certainly continued, that w e can get
Colorado avalanche deaths d o w n to zero. I only wish w e could get fools
to hear and understand the dangers that you warn about are no joke, and
to take those warnings seriously.
Keep up the good work, and hope to hear from you next year.
p'o'box 2™oY'24
M I N T U R N
M I D D L E
S C H O O L
™%c3?L8?7q£D2*?
March 16, 1988
Eagle County Commissioners:
Yearly, Che Minturn Middle School 7th graders participate in an
interdisciplinary Snow Unit.
in our enviornment.
Our objective is to understand survival
This year we were very fortunate to have a speaker
from the Colorado Avalanche Information Center, which had not been
available in the past.
Nick Logan presented information using lecture with slide and film
presentations.
He covered all of the aspects of snow safety, avalanches,
awareness while skiiing or being in the back country and general information
about snow.
His talk was very profound and informative.
He addressed the
audience on their level.
I understand Eagle County helps support the Colorado Avalanche
Information Center and we hope they continue to do so because they are
a valuable resource.
r
'v^thJvd-
" l i u ^
i
Cji
jf
&
7th Grade Teachers
cc:
Nick Logan
*j
x^
J
C
o
O
l
u
o
r
t
d
a
o
d
o
o
r
s
Published by the Colorado Department of Natural Resources, Division of Wildlife,
and dedicated to the conservation and enjoyment of Colorado's outdoors — Its
animals, fish, soil, forests, prairies and waters.
V o l u m e 37
S
B
a
a
f
c
JANUARY-FEBRUARY
e
g
k
u
c
a
o
r
u
d
n
By ERROL WILLETT
P H O T O BY RICHARD ,\RMSTRONG
ON FEBRUARY 19, 1987, five
skiers at the Breckenridge ski area
eyed the deep untracked powder on Peak
Seven from the rope that marks the ski
area boundary. Passing a large danger
sign and heading into the uncontrolled
area seemed a smallriskcompared to the
fun of the deep powder skiing awaiting
them. But seconds later, four of the five
were buried in an avalanche that held the
state and much of the country breathless
for 48 hours. They did not survive.
The snow was described as "like concrete" and had piled up as high as 40 feet
where the avalanche came to rest. The
fracture line near the top of the bowl was
a half mile wide and up to 10 feet deep.
The victims weren't equipped for avalanche danger and hadn't heeded the
numerous warning signs. They didn't
have a chance.
Thousands of skiets take the same risk
every year. Most are concerned more
with losing their lift pass than losing their
life. M a n y are experienced skiers, but
ignorant of backcountry safety equipment and prediction methods that could
turn the odds in their favor if they decide
to "go for it."
In a 1986 slide on Berthoud Pass, Ron
Brown was luckier. The veteran snow-
i
t
n
r
1988
NO. 1
g
C
o
l
o
y
The Avalanche Information Center
is the early warning system
for backcountry travelers
safety patrolman narrowly escaped, in
large part due to the experience and quick
work of tow partners. Back at work at the
Berthoud ski area shortly after the accident. Brown confessed that his knowledge of snow science accounted for only
50 percent of his avalanche forecasting.
"The rest is intuition," he said.
W h e n Brown went down in the slide
he knew to free himself of his daypack
and poles and to use a swimming motion
.^Telephone numbers to the ^
''"?. Colorado Avalanche ''7't. -\Information Center hotlines: ,,
Denver/Boulder 11 ^ "tV>- 236-9435
Ft. Collinsif*?-'- -i ?iV:V; 482-0457 j
Colorado Springs .71 r:r: 52Pj0020 .
Dillon (all Summit'J*5>h:'f^ ^ ' • H
;' County); fj-V-.I••: i;'.; 1468-5434
Vail .;'*:Y>V;;^ (".•;': vVl 827-5687 I
Aspen; r ^ y V : ; . : n v ^ v . ^ ? ° - > 6 6 4 j
Durango'^H.:V:;:-I:':V247-8187 i
ci.UiJlj JSuli.
--*••iil^_
••-•'l-£-;;i£J.
• ••'-•^.iSf.Uis^.iJ
to stay near the top of the snow. W h e n the
slide stopped he fanned an air pocket in
front of his face. Brown wore a transceiver, a device that emits and receives a
radio signal. His partners also were
equipped with transceivers as well as
shovels and experience. Most groups
aren't this well prepared.
A n d so K n o x Williams. Director of
the Colorado Avalanche Information
Erroll Willelt is a free-lance writer living in Center, predicts at least four skiers won't
be so fortunate this year. That's the yearBoulder, Colorado. During the winter he
teaches handicapped people to ski at the Win- ly average in Colorado, and he credits the
Avalanche Center's forecasting and inter Park ski area.
January/February 1988
r
a
d
o
'
s
formation hotline with helping to keep
the number of fatalities that low, despite
continuous increases in skier use.
The Breckenridge disaster is the worst
on record in Colorado, a state with the
distinction of having the most avalanche
fatalities in the U.S. since 1950. But the
numbers are low w h e n compared to the
1910 disaster that buried 96 passengers
inside tow train cars crossing Stevens
Pass in northern Washington, the most
deadly avalanche in recent American history. O r when compared to the 1970 ice
avalanches in Peru that overwhelmed the
city of Yungay, killing 20,000.
The Colorado Avalanche Information
Center w a s originally part of a U.S.
Forest Service program headquartered at
Ft. Collins. T h e program included research in snow science and avalanches
but that part of the funding was cut by the
Forest Service in 1985, ending the last
significant snow science study in this
country.
"It's an area of research where w e still
have a lot of work to do," says Williams.
"Currently, however, the Japanese and
Europeans are doing it."
Despite the cutbacks in research,
funding for the Avalanche Center has
continued. In addition to the $50,000
from the Forest Service, the Center also
receives funds from Colorado Ski Country, Rocky Mountain National Park, the
Colorado Division of Parks and Outdoor
Recreation, the Colorado Department of
Highways and some ski areas. Williams
operates the Center's telephone hotline
from a small office provided by the
29
National Weather Service in their headquarters near Stapleton International Airport in Denver.
The hotline has local numbers in
Aspen. Dillon, Durango, Vail, Ft. Collins, Colorado Springs and Denver/Boulder It provides daily updates on backr
country weather and snow conditions.
Areas arerisk-ratedlow, moderate,_or
high- The information is essential for
recreationisls beginning a backcountry
ski-tour, snowmobile ride or m o u n taineering expedition.
Betsy Armstrong, avalanche specialist
and co-author with Williams of The Avalanche Book, says the Breckenridge slide
was an "accident waiting to happen." It
was a classic soft-slab avalanche, the
type that create huge white clouds and
m o v e at speeds up to 200 miles per hour.
It occurred after nearly two feet of
fresh snow had fallen on a weak layer of
sugar snow, known by the experts as
temperature-gradient snow and often described as ball bearings or marbles.
Temperature-gradient snow is formed
when the snow crystals near the bottom
of the snowpack are altered by the passage of water vapor from the warmer
layers at ground level up through colder
layers. This rising water vapor freezes,
forming rounded, larger crystals that are
poorly bonded to one another.
Temperatures after the storm at Breckenridge remained cold, preventing the
newly fallen snow from settling and stabilizing. (Warming after a storm will
make snow more cohesive as a unit.) Ski
patrollers across the state were thinking
avalanche. The Avalanche Information
Hotline reported moderate-high risk.
Colorado hadn't had the continuous,
heavy snowfalls that create a homogeneous, well bonded snowpack. A n d the
forecasters knew that the majority of avalanches happen during and immediately
after storms.
W h e n asked h o w the accident at
Breckenridge could have been prevented. Brown responded, "skiers enjoy
the solitude in the backcountry. We're
not out here to tell people stop, don't go.
What we're saying is listen. D o your
homework."
N o one should be going into the backcountry without a transceiver, a shovel,
and a weather update from the Avalanche
Information Center's toll-free hotline,
says Brown. Brown does not use an avalanche cord and so is not sure if he wants
to endorse the device which trails behind
the skier and after a slide leaves a clue on
30
the surface to the buried skier's whereabouts. But he does recommend using
ski poles that screw together to form a
probing pole.
With experience, a buried skier can be
found with a beacon in minutes, and a
shovel works at least 10 times faster than
hands or skis. This can mean saving
someone's life. A n d it makes the cost of
the equipment, $150 to $200, seem inconsequential.
Brown, as well as m a n y experts, also
recommends becoming familiar with a
hasty snowpit, so named because it is
made hastily. The snowpit should be dug
on safe terrain in an area similar in aspect
to the steeper hill to be skied. It exposes
the layers in the snow which represent
the accumulations of different storms,
wind crust, and freezethaw. Hardness
can be tested by poking different layers,
and a shovel shear test shows h o w easily
the bonds between layers in the snow are
broken.
W h e n starting out on a questionable
slope, experts agree that skiers should
stay as high as possible so that if they
trigger a slide, there is a good chance it
will be below them. They recommend
crossing one at a time and following the
same track. Pack straps and pole straps
should be loosened so they can be quickly discarded should a slide occur. A n d
don't fall. M a n y avalanches are caused
by the third or fourth person across w h o
loses balance and falls. The slab under
stress m a y be able to support the skiers
but not the impact of the fall.
Climbing straight up a dangerous
slope is safer than using switchbacks
which are more likely to cause a horizontal fracture.
Experts agree there are no foolproof
techniques for, predicting snow slides,
only educated guesses. Experienced intuition is as valid a guide as computergenerated forecasts. Avalanches are
fluky. A s Armstrong says, " s n o w is a
nasty material to study. It's changing all
the time." So take the right equipment
along, heed hotline reports and the
advice of local ski patrollers.
A day after the last body was pulled
from the snow below Peak Seven, skiers
in a Breckenridge bar were asked if the
avalanche would change their view of
out-of-bounds skiing. Almost unanimously, the group agreed that skiers
would continue their cavalier, powderbasing despite the tragedy. Let's hope
they take their beacons and shovels
along. •
T h e D e n v e r Post
M
A
v
a
l
a
n
e
c
h
t
e
deaths
decrease
this year
By Paul Hutchinson
Denver Post Stall Writer
A more stable snowpack m a y explain w h y
deaths in the high country have fallen from 11
last winter to five for the 1987-88 season, according to avalanche experts.
Rut they caution that recent snows m a y
m a k e conditions treacherous for the next several days.
"The snowpack has been a little more stable
this winter." said Andy Loving of the Colorado
Avalanche Information Center.
'Pretty good shape'
New snow coupled with strong winds ''could
make conditions a little tender" for several
more days, Loving said. "But 1 think we're In
pretty good shape for the rest of the year."
The avalanche center counted about 1,200
slides through February of this year, compared
with 1,400 for the same period last winter.
Twenty-five people.have been involved in av&
Janches this year, compared with 51 last year.
The II deaths last winter marked the most
deadly Colorado avalanche season In R0 years,
since a time when "white death" posed a far
Erealer threat to miners than" to outdoorsmen.
ast year's total Included four skiers who died
In a single, massive slide while skiing out-ofbounds at Breckenridge.
r
o
1 a b o v e average
The five deaths this year are one above the
average for winters since 1080, Loving said. The
toll includes two cross-country skiers who died
In Second Creek Basin on Berthoud Pass, and.
three back country skiers killed south of Aspen.
In both cases, carelessness was a factor. The
Berthoud Pass skiers — although knowledgeable about the back country — inexplicably
failed to equip themselves with beacons, avalanche, cords and probes or shovels. And the
three skiers killed near Aspen Ignored warnings
about dangerous conditions.
The timing of the Berthoud Pass slide helped
bring attention to Avalanche Safely Week, a
'January series of lectures and demonstrations
across the state: Attendance in the DenverBoulder area topped 1,000, according to organizer Howard Paul.
But Paul was hesitant to credit better awareness for this year's drop in deaths.
"That would be too presumptuous; But the
timing of that avalanche certainly worked to
our advantage. S o m e good c a m e out of It,'! Paul
said..
Crackdown
Last year's avalanche deaths prompted some
mountain sheriffs to crack down hard on skiers
at commercial areas w h o Venture out' of
bounds. Apparently, skiers are taking heed.
Out-of-bounds skiing has decreased in San Miguel, Summit and PiUdn counties this season,
sheriffs say.
San Miguel Sheriff Bill Masters said a few
skiers have been cited for going Into areas
posted as closed, but generally the practice is
on the decline. Masters has arrested only one
out of-bounds skier this season.
"Overall, I think there Is a maturing process
going on a m o n g our back-country skiers," Masters said.
The Associated Press contributed to this report. •
L
E c o n o m i s t
s e e s
By J O H N R E B C H O O K
Rocky Mountain N«tvs Real Esta1« Editor
DALLAS — The Denver-area economy will continue to
sutler In 1988, despite some Improvements In telecommunications and cxporLi, • top economist said at a national
homrbuHdcn convention yesterday.
Lawrence HnrwiU, chief economist (or Wharton Econometric? In Bala-Cynwyd, Pa., said the Denver-area economy
has yet to hit bottom.
"I think it's going to go loner," said HorwlU, following a
panel discussion at the National Association of H o m e Builders 44th annual convention )n Dallas.
Horwltz, whose topic was "Regional Economies — What
Is Hot and What Is Not." said Denver Is definitely not hot.
"Basically, there Is a glut of oil," Horwiti said. "Our own
predictions put oil stabilising at about $17.50 per barrel. But
l SaH ornf IScrange,
h areas
e like Denver are
If Atheyvstayaat the
!;olng to be hurt. Energy Is still a big piece of the economy
orpthatrentire
e dregion."
iction
m o s t l y
o
c
a
l
g l o o m y
' 8 8
f o r
D e n v e r
The only economic bright spots appear to be telecom- uld. He said most of the over-appraising of bouses tool
place In the states that depended on the energy business,
munications and exports, he said.
"I would expect that part to do a lot better," Horwltz said. which helped lead to the record number of foreclosures.
"On the other hand, you have so much overbuilding that It to However, Merrill Butler, president of the American Real
going to take years to clean up. Your absorption rate is not Estate Group, said that he believes Colorado will rcbounrl
slowly. American Real Estate Group, based In Irvine, Calif,
very strong."
In a separate panel discussion, financial experts estimated b a private organization that helps financial Institution*
there are $500 billion In troubled real estate loans nation- work out their real estate and loan problems.
"I see Colorado as slowly recovering," Butler said "But 1
wide.
Michael Sumlchrast, senior economic adviser (or the Na- don't see any quick recovery. You lust have to sweat It out."
tional Association of H o m e Builders, said a large majority of Since April 1965, the organization has disposed of more
the loins, either In foreclosure or default, are located In oil- than $1.8 billion In troubled real estate lor lenders.
In Colorado, his group took over the Lake wood Sheraton
patch states such as Texas and Colorado.
"It's huge, It's large, it's difficult to define, and I don't Hotel for the lender, renovating It and changing the managethink its disappearing," Sumlchrast said. "The major, abso- ment. He also is Involved In several properties along the
lutely overriding problems Mre found In the 10 oil states." Western Slope, Butler said.
Butler said he b unwilling to unload properties at fire-sale
One of the main culprits are houses that dropped bi value
along with oil prices, said Gary Kramkh, chairman of the prices.
"If I can't sell It, we will hold It on the books, change the
board for the Federal H o m e Loan Bank Board m Des
management and wait for the market to Improve."
Moines, Iowa.
"The oil belt states really are the problem," Kramllch
art
By M I C H A E L R O M A N O
Rocky Mountain N«w« Staff Writer
If weather forecasting Is so Inexact science, predicting avalanches In Colorado's
high country Is an Imprecise art — a subjective combination of raw data and expert
Intuition
Yet this blend of science and guesswork
has become a well-established part of the
state's wintertime weather forecast, helping outdoor enthusiasts pinpoint the different levels of avalanche danger In three
regions of Colorado's backcountry.
"You never really know when (an avalanche will occur) — and you never really
know wbere, at least up to a point," said
Dale Atkins, one of lour forecasters with
the Colorado Avalanche Information Center In Denver. "We've got good ideas. It's
not a science. It's an art. And It's very
difficult to quantify "
WHAT CAN be quantified Is the human
cost During the 1986-87 season, 11 people
died when tons of snow unexpectedly hurtled down Colorado mountains. It was tbe
worst season for avalanche deaths In 81
years — three times the average number
of avalanche deaths in the state. So far this
year, five skiers have died In avalanches.
"What we try to do," says Knox Williams, the director of the avalanche center*
"is give people the chancetoplan their
outing. Once they go Into the backcountry,
the responsibility for safety Is theirs."
More than 23,500 rails were placed to
the seven phones lines across the stale that
include an avalanche-warning message
taped twice each day by one of the center's
tour forecasters.
THE NATIONAL rub"clly surrounding
last year's death toll helped altract statewide support and contributions for the avalanche renter, which opened IS years ago
In
Fort operating
Collins as onparta 1110,000
of the U.S.
Forest
Service.
Now,
budget
as
Avalanche forecaster Dale Atkins says, " Y o u never
really k n o w w h e n (an avalanche will occur) — and you
part of the Colorado Department of Natural Resources and the state Geological Survey, the avalanche renter Is housed In a
cramped cubicle In a comer of the National Weather Service office east of Stapleton
International Airport.
"There's a certain segment of the population that will take any kinds of risks,"
said John Rold, a state geologist and the
director of the Colorado Geological Survey.
"But there's a much larger srgment of our
population that, if they know the risks and
are able to evaluate the conditions, will
make reasonable, logical choices, and
avoid risks. That's why the avalance center
is so Important"
Last year, forecasters recorded 1,960
avalanches — or about 3 % above normal
during the six-month season. This year,
nearly 1.000 slides have been registered —
110 last Wednesday alone. For each one
UNOA McCTIMKU/nocfcv Mowttfn K m
never really k n o w where, at least u p to a point. W e ' v e
got g o o d Ideas. It's not a science. It's an art."
reported, 10 go unseen, the center estimates.
The avalanche forecast begins to develop
each morning at about 0:30. when weather
data and other Information begin arriving
by phone from 30 spotters scattered
throughout three avalanche regions — the
northern, central and southern mountains.
DATA INCLUDING cloud cover, temperatures, the weight of the snowpack and
most Importantly, the amount of new snow
and the strength of the winds go Into avalanche-danger forecasts.
Atkins said the Increasing avalanche
dangers In the backcountry stem Irom two
key factors: more cross-country skiers, hikers aTid snowmobllera using tbe pristine
backcountry lor recreation, and slideprone snow conditions. This year and last,
weak, early snowpacks were covered with
later snows that formed "slabs" above the
unstable layer.
"Whenever the stress of too much snow,
or (the weight of, a skier or a snowmobiler
Is equal to or greater than the strength of
the slab, you're going to have failure," said
Atkins.
Individuals who venture Into the backcountry, Atkins said, should be able to Interpret "clues" that might Indicate the
threat of an avalanche. They Include the
presence of more than It Inches of new
snow, snowlall of greater than an Inch and
hoar, wind-driven snow drifts, rapid
changes In temperatures and slope steepness between 30 and 43 degrees.
"We're not going to keep them out of the.
backcountry," Atkins said. "But they need
to be educated. The best way to be sale is
to avoid avalanche areas. And look for
those clues."
Summit
S£Nnne.u
Lsllem
T
h
i
n
k
' s n o w
Editor:
I wish to lhank Beaver R u n Resort in
Breckenridge for donating its conference
center facilities for the free avalanche
awareness seminar I held there on the
evening of November II. A "thank
you** to K-Summit Radio and Television
is also in order as they continue to air
strong support for avalanche safety programs and related messages.
This provided an opportunity for 125
Summit County residents to learn more
about the avalanche phenomenon,
where and when avalanches are most
likely to occur, h o w to avoid them and
what to do in the event of an accident
while enjoying a backcountry outing.
U p o n signing in, almost everyone
checked off that they would be interested in a more advanced avalanche
course, including a field session, in the
future. I will certainly do what I can to
accommodate these desires.
The avalanche season is upon us.
Already, four backcountry skiers
have been caught in separate accidents
in Colorado. Three of the incidents had
the potential to be quite serious. O n e of
the victims was totally buried and not
breathing when finally rescued by other
members of his party (he lived); another
W e
w a n t
s a f e t y '
was buried u p to his chin and had to be
dug out of his vice-like entrapment; and
the third sustained injuries when he was
swept over a cliff by the moving snow.
The season has only begun and the
snowpack, inherent to the Continental
Climate Zone of the Colorado Rockies
and S u m m i t County, is exhibiting
weakness in the form of a depth hoar
layer (uncohesive sugar snow) near the
ground. This layer m a y have a hard time
supporting the weight of subsequent
snowfall, or that of a backcountry skier,
and m a y collapse and avalanche. W e
can only hope that the parameters that
lead to this occurrence abate before the
condition worsens.
The staff at the Colorado Avalanche
Information Center want to instill a
strong sense of "snow safety" thinking
in the minds of backcountry users. This
will ultimately lead to more fun in the
snow and reduce the number of avalanche accidents-they can be avoided.
For local avalanche and weather information call 468-5434. This message
is updated daily.
Nick Logan
Associate Director,
^--°*°raJ9-.AyaJancrie
Information Center
y o u r
letters
The Summit Sentinel encourates your letters and will try to publish
all letters In a timely fashion.
Letters should be no more than two double-spaced, typewritten pates
In length, and must be signed by the author.
Clear, hand-printed letters will be considered for publication.
The letters will be edited for grammar, brevity and good-taste, but
wa will make every effort to retain the authorh original meaning.
Send your letters to Editor, the Summit Sentinel, P.O. Box 709,
FHtco. C O 80443.
B a c k - c o u n t r y
a d v i c e :
S t a y
F o r g e t all I he blather about
beepers and avvy cords.
Knox Williams, has just one
bil of advice about skjing
the Colorado back country these
days: stay the hock out.
" In the wake of the most recent
accident that claimed three skiers
near Ashcroft Sunday, the director
of the Colorado Avalanche Information Center has little else to offer in the vein of skier safety.
"This is the time to slick to established ski areas for a while until
the back country heals itself," said
Williams, w h o has been Involved in
avalanche forecasting since 1970.
; As the headlines that screamed
of the most recent tragedy —
bringing to five the number of
cross country skiers who have
been killed in snow slides this season — suggest, this is a dreadful
period to be footloose in the steep
mountain valleys. The current
problem is one that, at one stage or
another, repeats itself often In the
Rockies.
A sparse early snowfall, just
enough to establish a weak layer,
was followed by a period of dry
weather that caused this snow to
become metamorphosed into the
round crystals, m u c h like ballbearings, commonly known as sugar snow. Then, starting just before
Christmas, there has been a continuing series of storms that have
dumped from 50 to 70 inches over
m u c h of the high country.
The result is a snowpack ready
to roll anywhere the slope is steep
enough, whether there are skiers
to dislodge it or not. Present conditions are so volatile that not even
Ihe most experienced avalanchecontrol experts can predict where
or when the snow will break. There
are stories of ski patrolmen climbing trees before throwing their
explosive charges for fear that the
slide will start above them rather
than below. In m a n y cases, the
slides are breaking all the w a y
down to the ground, unleashing a
tremendous volume of snow.
W h e n conditions are this treacherous a little knowledge can be a
dangerous thing. T o paraphrase
the bumper slicker, stuff happens,
even lo experienced skiers.
"Snowfall and wind are the two
main at chllecls of avalanches,"
Williams said. "We've had plenty
of both and right now there's a ma-
s k i
o u t !
CHARLIE
M E Y E R S
jor hazard nearly everywhere. It
just isn't safe lo be anyplace where
there are sleep slopes."
Still, Williams doesn't believe
things now are as dangerous as
they were last spring, when a situation, unique for Colorado, conspired to create a hazard that resulted
in 11 deaths between .Ian. 8 and
March 15. Then, it was a heavy October snowpack that sat drying
out, rotting away lo sugar, for all
of November and December.
Williams thinks the present situation will improve in time, given the
proper conditions.
"What w e need is some w a r m ,
dry weather for a couple of weeks
lo allow the snowpack lo settle, to
form a strong mid pack snow layer. If thai happens, it would help
Ihe back country for the remainder
of the season."
That eventuality would pave the
way for what might be described
as "normal" conditions under
which the hazard increases with
each major slorm and Ihen diminishes in between, a situation far
preferable lo that of last spring.
"Last, year, w e never had a period of lesser hazard," Williams continued. "It was bad all the lime."
The best scenario now would be
a period of respite from storms in •
which the snow settles, allowing
Ihe snow grains to bond together
and the entire pack lo gain
strength. Only when this happens
should skiers venture into the back
country and then, Williams advises, they should do so gingerly.
For information on avalanche
danger in various locations, phone
the following numbers: Denver
236 9435, Fort Collins 482-0457, Colorado Springs 520 0020, Durango
247-8187, Aspen 920-1664. Dillon
468-5434, Vail 827-56f 7.B

1987/88 - Colorado Department of Education

Transcription

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