Dry Lightning

Dry Lightning
Experimental Products
Current Conditions
Forecast
Image Archive
Data Archive
Dry Lightning On Estimated Rain
Dry Lightning on Dryness Levels
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Google-Earth KMZ
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Dry Lightning
Regional Subsets
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Dry lightning occurrence is of critical importance to land management agencies since this type
is most likely to cause wildland fires. Dry lightning is cloud-to-ground (CG) lightning without any
accompanied rainfall nearby. Recent dry lightning research has concentrated on using upper air
measurements--atmospheric stability and moisture content to predict dry lightning episodes in
advance (Rorig and Ferguson 1999). Spatial products are needed to give managers an idea of
where dry lightning has occurred immediately after the storms have passed.
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Dry Lightning
National
polarity
(Cummings
and
rainfall
others,
Dry
data
based
Lightning
Weather
2002)
et.
are
lightning
al
adjusted
1998).
Services
is
Maps
used
density
are
A
for
in
Lightning
(NWS)
made
the
grids,
dry
24-hour
Advanced
by
lightning
Fuel
produced
merging
hydrologic
type
cell
Hydrologic
daily
grid
from
calculation.
converted
day
estimated
daily
(ending
Prediction
cloud
The
from
rainfall
to
at
lightning
a
ground
1200GMT)
Service
cover
grids,
lightning
strike
type
(AHPS),
produced
used
map
and
strike
by
with
(Schmidt
estimated
by
AHPS.
the
two
data
All
density
met
classified
Dry
occur
lightning
three
lightning
in
and
a
have
as
criteria:
cell,
estimated
barren,
cells
density
adryness
the
4km
rainfall
are
cell
urban
pixel
grids
displayed
rainfall
is
classified
less
size
or
are
water),
grids
than
in
based
which
as
0.10in
are
and
"positive".
on
recreated
the
one
a(0.25in
strike
lightning
positive
for
positive
polarity.
for
daily.
or
fuel
the
negative
Aby
and
Southern
type
Ifboundaries.
dry
both
one
lightning
grid
cloud
positive
for
is
and
negative
static
to
cell
Eastern
and
ground
and
exists
negative
lightning
the
map),
lightning
when
lightning
fuel
strikes
strikes.
itusing
has
strike.
(not
Two
while
maps
the
2nd
are
displays
displayed.
the
One
dry
lightning
shows
dry
cells
lighting
overlying
the
overlying
current
the
fuel
24
"dryness"
hour
estimated
levels
(rainfall
ww.predictiveservices.nifc.gov/outlooks/7-Day_Product_Description.pdf
http://w
).
fire
The
data.
data
combination
occurrence.
24
from
The
hour
the
fuel
of
estimated
regional
one
These
or
two
Geographic
levels
dryness
rainfall
fuel
are
is
dryness
levels
compiled
made
Area
are:
and/or
on
Coordination
by
aW.
daily
AHPS
fire
basis
weather
using
Centers
area
the
indices
(GACC).
NWS
River
which
Office
Forecast
Dryness
correlate
in
Missoula
Center
level
well
is
(RFC)
to
athey
large
or
no
probability
Moist
(Green):
of
critical
new
Indicates
large
weather
fires
acreated,
events.
burn
or
significant
environment
growth
which
on
has
existing
historically
fires,
even
resulted
when
in
aavailable
very
probabilities
critical
Dry
weather
(Yellow):
new
or
ignition
Indicates
large
fires
trigger
afuels
or
transitional
event.
significant
burn
growth
on
existing
that
fires
typically
unless
results
accompanied
in
low
by
athe
-grids
a
accompanied
higher
Very
than
Dry
normal
by
(Brown):
a
critical
probability
Indicates
weather
of
aU.S.
significant
very
ignition
dry
burn
trigger
fire
growth
environment
event.
and
new
which
fires,
has
especially
historically
when
resulted
in
where
humidity
Areas
expected
relative
very
have
dry
a
that
for
pre-existing
much
humidity
fuels.
create
wind
to
the
occur
higher
Dry
Storm
and
a
are
“Critical”
where
lightning
fuel
relative
likelihood
issued
Prediction
conditions
dry
humidity
cells
when
‘Extreme”
of
Center
within
igniting
very
combined
exist.
are
strong
these
have
Fire
issued
Extremely
a
wildfire.
Weather
with
delineated
areas
winds
when
weather
Critical
should
and
Area
strong
as
very
conditions
Fire
are
a
be
winds
significant
low
given
also
Weather
RH
(>20mph)
shown.
close
such
are
threat
Areas
expected
as
scrutiny
Critical
wind
and
for
for
wildfires
low
wind
or
since
Fire
to
relative
RH
occur
and
Weather
are
with
There
based
Southern
other
regions
are
on
area
Geographic
regional
use
maps
an
differences
have
estimated
Area
aor
Coordination
rainfall
in
rainfall
the
threshold
the
threshold
definition
Center
for
(GACC)
of
acells
of
dry
0.10
a
lightning
dry
inches.
lightning
event
strike.
The
of
0.25
Eastern
Maps
inches
are
and
or
less.
All
References:
Cummins,
combined
Geophys.
Res.
TOA/MDF
K.L.;
103:
Murphy,
9035-9044.
technology
M.J.;
Bardo,
upgrade
E.A.;
of
Hiscox,
the
U.S.
W.L.;
National
Pyle,
Lightning
R.B.;
Pifer,
Detection
A.E.
1998.
Network.
A
J.
Rorig,
Pacific
M.L.
Northwest.
and
S.A.
J.
Ferguson,
Appl.
Meteor.,
1999:
38:
Characteristics
1565-1575.
of
lightning
and
wildland
fire
ignition
inlow
Schmidt,
of
RMRS-GTR-87.
Mountain
coarse-scale
K.M.,
Research
J.
spatial
Fort
P.
Station,
Menakis,
Collins,
data
for
41
CO:
C.
wildland
pp.
C.
+CD
Hardy,
Department
fire
and
J.environment
fuel
Hann,
of
management.
Agriculture,
and
D.
L.
Bunnell.
Forest
General
Service,
2002:
Tech.
Development
Rocky
Rep.
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