update for the mariana islands

EL NINO—SOUTHERN OSCILLATION:
UPDATE FOR THE MARIANA ISLANDS
Charles ‘Chip’ Guard
Warning Coordination Meteorologist
Weather Forecast Office Guam
Tralaje Business Center
Hagatna, Guam
28 May 2014
BACKGROUND
• Last major El Nino was in 1997 —very strong and very wet; Typhoon Paka
• Last major El Nino‐related drought was in 1998 —very dry
• La Nina conditions occurred in 1999, 2000, and 2001 —very wet spring
• Moderate El Nino conditions in 2002—no significant drought in 2003; Typhoons Chata’an and Pongsona
• Now nearly a decade of alternating El Nino and La Nina events, but with La Nina dominating in terms of impacts.
BACKGROUND
El Nino Events
La Nina Events
What is ENSO?
• ENSO or the El Niño—Southern Oscillation refers to the ocean—atmosphere climate system of the equatorial Pacific Ocean
What is El Niño?
• El Niño is the warm phase of ENSO or basically nature’s way of redistributing excess heat from the western equatorial Pacific Ocean to the central and eastern equatorial Pacific
What is La Niña?
• La Niña is the cold phase of ENSO or the oceanic response to persistent, stronger than normal equatorial easterly winds
What is ENSO‐Neutral?
• ENSO‐neutral is the intermediate phase between El Niño and La Niña events
How long have we had El Nino Events?
Geological Set‐Up for El Nino
ENSO Cycles
NORMAL CONDITIONS ACROSS THE EQUATORIAL PACIFIC
Warm
Cold
EL NINO NEUTRAL CONDITIONS IN THE EQUATORIAL PACIFIC
EL NINO ONSET CONDITIONS ACROSS THE EQUATORIAL PACIFIC
Warm
Cold
EL NINO ONSET CONDITIONS IN THE EQUATORIAL PACIFIC
EL NINO CONDITIONS IN EQUATORIAL PACIFIC
LA NINA ONSET CONDITIONS ACROSS THE EQUATORIAL PACIFIC
Warm
Cold
EL NINO MONITORING REGIONS
S
D
A
+1.5C mod
J
weak
S
-1.5C
-2.5C
J
EL NINO CYCLE
+1.5C strong
+1.0C mod
+0.5C
C weak
Ap
J
S
Jl
D
A
Wet
Dry
S
0.0C
0.0
-0.5C
-1.0C
-1.5C
J
Ap
Moderate EN
Weak—every 3-5 years
Moderate—every 7-10 years
Strong—every 15-30 years
Wet
Moderate EN
EL NINO FREQUENCY
•
Weak
3-5 years
• Moderate
7-10 years
• Strong
15-30 years
• El Niño is an aperiodic event
•An El Niño usually has a wet period
and a dry period
EL NINO INTENSITY
•
Weak
+0.5ºC/~+1ºF
• Moderate
+1.0ºC/~+2ºF
• Strong
+1.5ºC/~3.5ºF
• Intensity ≈ Severity of Impacts
•An El Niño usually has a wet period
and a dry period; it also has sea level
changes
El Niño Alert System
ENSO ALERT SYSTEM: El Niño or La Niña Watch: Issued when conditions are favorable for the development of El Niño or La Niña conditions within the next three months.
El Niño or La Niña Advisory: Issued when El Niño or La Niña conditions are observed and expected to continue.
Final El Niño or La Niña Advisory: Issued after El Niño or La Niña conditions have ended.
NA: ENSO Alert System is not active.
El Niño Alert System
The Climate Prediction Center defines. . .
"El Niño conditions" as existing when:
A one‐month positive sea surface temperature anomaly of 0.5C or greater is observed in the Niño‐3.4 region of the equatorial Pacific Ocean (5ºN‐5ºS, 120ºW‐170ºW) and is expected to persist for at least three consecutive months AND
An atmospheric response typically associated with El Niño is observed over the equatorial Pacific Ocean (see The ENSO Cycle).
"La Niña conditions" as existing when:
A one‐month negative sea surface temperature anomaly of ‐0.5C or less is observed in the Niño‐3.4 region of the equatorial Pacific Ocean (5ºN‐5ºS, 120ºW‐170ºW) and is expected to persist for at least three consecutive months AND
An atmospheric response typically associated with La Niña is observed over the equatorial Pacific Ocean (see The ENSO Cycle). TWO TYPES OF ISLANDS
•
High Islands
• Low Islands
• Each type of island has specific
drought-related problems, but low islands
are most harshly affected
HIGH ISLAND HIGH ISLANDS
LOW ISLAND Pisarach Island
LOW ISLAND EL NINO EFFECTS AND IMPACTS ON PACIFIC ISLANDS—WET PERIODS
• Enhances westerly winds along equator —coastal flooding and erosion; some wind damage
• Enhances monsoon activity across Micronesia —
flooding, mudslides, and coastal erosion
• Shifts tropical cyclone development eastward, increasing risk to the Marshall Islands, eastern FSM, the Mariana Islands, and American Samoa —wind damage, storm surge, flooding, destruction of food crops
• For the CNMI, it increases the risk of tropical cyclones by a factor of 3 —strong ENs are the most severe
EL NINO EFFECTS AND IMPACTS ON PACIFIC ISLANDS—DRY PERIODS
• Drought occurs in all of Micronesia in Jan‐Apr following a strong El Nino event; it starts in late Fall in Palau; Yap & Chuuk States usually dry in moderate El Ninos; the Marianas can be wet or dry.
–
–
–
–
Water resources greatly reduced or disappear
Health can be drastically affected
Fire danger greatly enhanced
Trade winds increase, raising sea levels and causing coastal flooding
– Food sources may not return for 8‐10 months
• On many islands, drought is not an inconvenience, but a life or death issue
EL NINO EFFECTS AND IMPACTS ON PACIFIC ISLANDS—DRY PERIODS
SALT WATER
SAIPAN AQUIFER
EL NINO EFFECTS AND IMPACTS ON PACIFIC ISLANDS—DRY PERIODS
• Drought occurs in all of Micronesia in Jan‐Apr following a strong El Nino event; it starts in late Fall in Palau; Yap & Chuuk States usually dry in even moderate El Ninos; the Marianas can be wet or dry.
–
–
–
–
Water resources greatly reduced or disappear
Health can be drastically affected
Fire danger greatly enhanced
Trade winds increase, raising sea levels and causing coastal flooding
– Food sources may not return for 8‐10 months
• On many islands, drought is not an inconvenience, but a life or death issue
LA NINA EFFECTS AND IMPACTS ON FSM PACIFIC ISLANDS
• Many locations can have a wet spring (Jan‐Apr)
– Kosrae can get 60‐80 inches of rain in Jan‐Mar, but the Marianas can be wet or dry
– Tropical cyclone activity pushed to the west; reduced threat for the Mariana Islands
– Strong trade winds can elevate sea levels, causing increased coastal erosion and coastal inundation EL NINO—SOUTHERN OSCILLATION ASSESSMENT TOOLS
OCEANIC PARAMETERS
• Equatorial sea surface temperature anomalies
• Equatorial sub‐surface ocean temp anomalies
• Sea level heights
• Climate model predictions
SEA SURFACE TEMPERATURE
2009‐2010 El Nino
RECENT SEA SURFACE TEMPERATURES
PACIFIC SEA SURFACE TEMPERATURES
SUB‐SURFACE OCEAN TEMPERATURES IN THE EQUATORIAL PACIFIC
SUB‐SURFACE OCEAN TEMPERATURES IN THE EQUATORIAL PACIFIC
SCRIPPS CLIMATE PREDICTION MODEL ANOMALIES
NCEP CLIMATE PREDICTION MODELS SST ANOMALIES
OTHER CLIMATE PREDICTION MODEL SST ANOMALIES
WORLDWIDE PREDICTION MODEL ANOMALIES
IRI PROBABILITIES OF EL NINO, LA NINA, ENSO‐NEUTRAL
SEA LEVEL CHANGE DURING EL NINO
+ 24”
- 12”
EL NINO—SOUTHERN OSCILLATION ASSESSMENT TOOLS
ATMOSPHERIC PARAMETERS
•
•
•
•
•
Southern Oscillation Index
Equatorial wind anomalies
Near equatorial vertical motion fields
Rainfall and tropical cyclone patterns
Climate model predictions
El Nino: Positive SST & Negative SOI; La Nina: Negative SST & Positive SOI
Normal Flow
L
H
Southern Oscillation—El Nino Flow
H
L
Wind Anomalies
Wind Anomalies
VERTICAL MOTION AND RELATIVE HUMIDITY (East‐
West along Equator)
VERTICAL MOTION AND RELATIVE HUMIDITY (North‐South averaged 120E‐170E)
OUT‐GOING LONGWAVE RADIATION
Saipan
Monsoon
SEPTEMBER 16, 2002
Saipan
Monsoon
OCTOBER 23, 2002
Tropical Storm Faxai
Pohnpei
Kosrae
2300Z 13 DEC 2002
EL NINO‐‐INCREASED Threat
LA NINA‐‐DECREASED Threat
La Nina
El Nino
30N
20N
"El Nino Box"
10N
EQ
120E
100E
1997
140E
1998
Chuuk
160E
180
Majuro
ENSO Tropical Cyclone Patterns
El Nino Pattern
La Nina Pattern
Current Atmospheric Indicators
•
•
•
•
•
Periods of persistent westerly winds
Eastward displacement of westerly winds
Enhanced convection near the date line
Eastward displacement of early season TCs
High number of early season TCs
Current Oceanic Indicators
• Dramatic deepening of the upper warm layer of the equatorial eastern & central Pacific
• Rapid fall in the sea levels of the western Pacific
• Large area of enhanced sea surface temperatures near the date line
Predicted Typhoon Risk for Islands from
June 2014 through June 2015 is as follows:
Inclusive Period
Tropical Cyclone Risk
SW Islands
CNMI/Guam
SE Islands
Jun 2014-Sep 2014
10% chance
35% chance*
Oct 2014-Dec 2014
10% chance
70% chance
25% chance
Jan 2015-Mar 2015
10% chance
25% chance
10% chance
Apr 2015-Jun 2015
5% chance
10% chance
5% chance
20% chance
* 70% if the Northern Islands are included
We expect El Nino conditions in the Summer of 2014 with a
peak in December.
Super Typhoon Choi‐wan
passes over Alamagan Island
OBSERVED SEA LEVEL (MONTHLY AVERAGE)
0.8
0.6
0.4
0.2
0
-0.2
YEAR
La Nina: Sea level
El Nino: Sea Level
19
97
19
96
19
95
19
94
19
93
19
92
19
91
19
90
19
89
19
88
19
87
19
86
19
85
-0.4
19
84
HEIGHT (Ft amsl)
1
GUAM ANNUAL RAIN
160
NOTE: RED INDICATES POST EL NINO YEARS
140
120
100
NORMAL
80
60
40
20
2000
1998
1996
1994
1992
1990
1988
1986
1984
1982
1980
1978
1976
1974
1972
1970
1968
1966
1964
1962
1960
1958
1956
1954
1952
1950
0
NOTE: POST-EL NINO YEARS IN RED; STARS ARE LA NINA
Percent of Normal
180
EL NINO YEAR
YEAR AFTER EL NINO
160
140
120
NORMAL
100
80
60
40
20
0
1
JAN
2
3
4
5
6
7
8
9
10
11
12
13
JAN
14
15
16
17
18
19
20
21
22
23
24
25
JAN
Predicted rainfall for the Mariana Islands from
June 2014 through June 2015 is as follows:
Inclusive Period
Jun 2014-Sep 2014
Oct 2014-Dec 2014
Jan 2015-Jun 2015
% of long-term average
all locations
110%
120%
70%
We expect El Nino conditions in the summer of 2014 with a
peak in December.
Relocation
DS
Farallon
NA
SI S
LA N
144°E
140°E
A
I
AR
M
148°
Saipan
152°
156°
160°
164°
Tinian
Aguigan
Rota
Guam
8°
Ulithi
Fais
Yap
Ujelang
Gaferut
Murilo
Faraulep
West Fayu
Sorel
8°
Olimarau
Oleai
Ifaluk
Eauripik
WES
Nanomuito
Lamotrek Pikelot
Elato
A RO LI N E
T ERN C
Inissifau Pissila
Chuuk
DS
Pulusuk
Kuop
Losap
Namoluk
Pakin
Oroluk
Nama
Pulowat
Satawal
I SL A N
Pulap
8°
Fayu Nomwin
.
EAS T ER N
Etal
CAR O
Ngatik
Lukonur
Satawan
Ant
LI N
Pohnpei
Pingelap
Mokil
EI
SL
A
ND
S
Kosrae
4•N
4•N
500km
140°E
Nukuoro
144°E
148°
152°
156°
160°
164°
Ulithi 29 III 07
Photo Fritz Collection MARC
Past Regional Cyclones—1907
Past Cyclones on Yap—1907
SUMMARY
• El Nino conditions should develop by the summer of 2014. • Tropical cyclone activity will likely be higher than it has been for the last decade. Expect 3‐4 typhoons in the area and around 5 monsoon episodes.
• Sea level should continue to fall below average values due to El Nino. Coral bleaching could develop next spring. Sea levels will rise in the summer.
Questions?
Guam
EL NINO ONSET CONDITIONS ACROSS THE EQUATORIAL PACIFIC
NORMAL CONDITIONS ACROSS THE EQUATORIAL PACIFIC
LA NINA ONSET CONDITIONS ACROSS THE EQUATORIAL PACIFIC
STORMS AFFECTING ROTA
Historical Typhoons:
–
–
–
–
–
–
–
–
–
–
–
–
Nov 1962—Super Typhoon Karen—Heavy damage
Apr 1963—Super Typhoon Olive—Heavy damage
Dec 1963—Typhoon Susan—Moderate damage
Nov 1967—Typhoon Gilda—Heavy damage; 500 homeless
May 1976—Super Typhoon Pamela—Heavy damage
Jan 1988—Typhoon Roy—Rota devastated
Jan 1990—Typhoon Koryn
Nov 1997—Super Typhoon Keith
Dec 1997—Super Typhoon Paka
Jul 2002—Typhoon Chata’an
Dec 2002—Super Typhoon Pongsona
Aug 2004—Super Typhoon Chaba
STORMS AFFECTING SAIPAN/TINIAN
Historical Typhoons:
– Apr 1963—Super Typhoon Olive—95% houses badly damaged; power and
water badly damaged; hospital lost roof; $4.4M
– Dec 1963—Typhoon Susan—90% houses damaged
– Apr 1968—Super Typhoon Jean—Devastated Saipan--90% houses
destroyed;1000’s homeless; $16M
– May 1976—Typhoon Pamela
– Jul 1976—Super Typhoon Therese—90-115 mph winds on Saipan
– Dec 1986—Super Typhoon Kim—1/3 power poles on Saipan down; $15M
damages on Saipan
– Sep 1991—Typhoon Mereille—Moderate damage
– Oct 1994—Typhoon Wilda—Much damage on Saipan and Tinian; many
ships sunk
– Nov 1994—Super Typhoon Zelda—Heavy damage to Saipan, Tinian &
Anatahan; Anatahan residents were evacuated to Saipan
– Nov 1997—Super Typhoon Keith—115 mph winds on Rota and Tinian
– Jun 2004—Typhoon Tingting
– Aug 2004—Super Typhoon Chaba
– Aug 2005—Typhoon Nabi