Gale Warning 308, NWS Anchorage, AK

037 
FZAK62 PAFC 042329 CCA
OFFALU

OFFSHORE WATERS FORECAST...CORRECTED
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 PM AKDT MON APR 4 2011

CORRECTED ZONE 414

OFFSHORE WATERS FORECAST FOR THE BERING SEA

WIND FORECASTS REFLECT THE PREDOMINANT SPEED AND DIRECTION
EXPECTED. SEA FORECASTS REPRESENT AN AVERAGE OF THE HIGHEST
ONE-THIRD OF THE COMBINED WIND WAVE AND SWELL HEIGHT.

PKZ499-051500-
400 PM AKDT MON APR 4 2011
.SYNOPSIS FOR CENTRAL BERING SEA...
A COLD FRONT EXTENDING FROM THE CENTRAL BERING TO THE KUSKOKWIM 
DELTA WILL TRACK TO THE WESTERN GULF TUE MORNING. A DEVELOPING
PACIFIC LOW WILL MOVE TO 47N 175E TUE AFTERNOON AT 986 MB AND THEN
RAPIDLY STRENGTHEN TO 945 MB AS IT MOVES TO 54N 178W WED AFTERNOON.
$$

PKZ411-051500-
BERING SEA OFFSHORE WEST OF 180 AND EAST OF THE INTERNATIONAL
DATELINE
400 PM AKDT MON APR 4 2011

...GALE WARNING THROUGH TUESDAY NIGHT...

.TONIGHT...E WIND 35 KT. SOUTH OF 56N...W WIND 35 KT BECOMING SW 20
KT AFTER MIDNIGHT. SEAS 19 FT. FREEZING SPRAY NORTH OF 56N. 
.TUE...E WIND 35 KT. SOUTH OF 56N...S WIND 15 KT BECOMING E 25 KT BY
LATE AFTERNOON. SEAS 14 FT. FREEZING SPRAY NORTH OF 57N. 
.TUE NIGHT...E WIND 25 TO 35 KT BECOMING NE 35 TO 45 KT AFTER
MIDNIGHT. SEAS 14 FT. SNOW AND RAIN. FREEZING SPRAY NORTH OF 57N. 
.WED...N WIND 55 KT. SEAS 24 FT. 
.WED NIGHT...N WIND 60 KT. SEAS 27 FT. 
.THU...NW WIND 60 KT. SEAS 26 FT. 
.FRI...W WIND 25 KT. SEAS 17 FT. 
.SAT...SW WIND 25 KT. SEAS 13 FT.  
$$

PKZ412-051500-
BERING SEA OFFSHORE 171W TO 180 AND NORTH OF 56N
400 PM AKDT MON APR 4 2011

...GALE WARNING TUESDAY NIGHT...
...HEAVY FREEZING SPRAY WARNING TONIGHT AND TUESDAY NIGHT...

.TONIGHT...NE WIND 15 TO 25 KT. SEAS 18 FT. HEAVY FREEZING SPRAY
MAINLY NEAR THE ICE EDGE. 
.TUE...E WIND 15 TO 25 KT. SEAS 15 FT. FREEZING SPRAY. 
.TUE NIGHT...E WIND 35 KT INCREASING TO 45 KT AFTER MIDNIGHT. SEAS
15 FT. SNOW. HEAVY FREEZING SPRAY MAINLY AFTER MIDNIGHT NEAR THE ICE
EDGE. 
.WED...E WIND 55 KT. SEAS 24 FT. 
.WED NIGHT...NE WIND 60 KT. SEAS 26 FT. 
.THU...NW WIND 55 KT. SEAS 25 FT. 
.FRI...NW WIND 45 KT. SEAS 22 FT. 
.SAT...SW WIND 25 KT. SEAS 13 FT.  
$$

PKZ413-051500-
BERING SEA OFFSHORE 171W TO 180 AND SOUTH OF 56N
400 PM AKDT MON APR 4 2011

...GALE WARNING TONIGHT AND TUESDAY NIGHT...

.TONIGHT...W WIND 35 TO 45 KT DIMINISHING TO 15 TO 25 KT TOWARDS
MORNING. SEAS 23 FT. 
.TUE...SE WIND 15 KT BECOMING E 20 TO 30 KT IN THE AFTERNOON. SEAS 16
FT. RAIN AND SNOW. 
.TUE NIGHT...E WIND 45 KT BECOMING S 35 KT TOWARDS MORNING. SEAS 14
FT. RAIN AND SNOW. 
.WED...SE WIND 50 KT. SEAS 21 FT. 
.WED NIGHT...W WIND 55 KT. SEAS 28 FT. 
.THU...NW WIND 55 KT. SEAS 30 FT. 
.FRI...NW WIND 40 KT. SEAS 25 FT. 
.SAT...SW WIND 25 KT. SEAS 14 FT.  
$$

PKZ414-051500-
BERING SEA OFFSHORE EAST OF 171W
400 PM AKDT MON APR 4 2011

...GALE WARNING TONIGHT AND TUESDAY NIGHT...

.TONIGHT...W WIND 35 TO 45 KT BECOMING NW 20 TO 30 KT. SEAS 22 FT.
FREEZING SPRAY NORTH OF 56N. 
.TUE...NW WIND 20 TO 30 KT...BECOMING E 15 TO 25 KT WEST OF 167W IN
THE AFTERNOON. SEAS IN ICE FREE WATERS 17 FT. RAIN. FREEZING SPRAY
NORTH OF 56N. 
.TUE NIGHT...E WIND 30 TO 45 KT. SEAS IN ICE FREE WATERS 12 FT. SNOW
AND RAIN. FREEZING SPRAY NORTH OF 56N. 
.WED...SE WIND 50 KT. SEAS IN ICE FREE WATERS 18 FT. 
.WED NIGHT...S WIND 60 KT. SEAS IN ICE FREE WATERS 27 FT. 
.THU...W WIND 60 KT. SEAS IN ICE FREE WATERS 33 FT. 
.FRI...NW WIND 45 KT. SEAS IN ICE FREE WATERS 26 FT. 
.SAT...W WIND 35 KT. SEAS IN ICE FREE WATERS 17 FT.  
$$

025 
FZAK62 PAFC 051147
OFFALU

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 AM AKDT TUE APR 5 2011

OFFSHORE WATERS FORECAST FOR THE BERING SEA

WIND FORECASTS REFLECT THE PREDOMINANT SPEED AND DIRECTION
EXPECTED. SEA FORECASTS REPRESENT AN AVERAGE OF THE HIGHEST
ONE-THIRD OF THE COMBINED WIND WAVE AND SWELL HEIGHT.

PKZ499-060300-
400 AM AKDT TUE APR 5 2011
.SYNOPSIS FOR CENTRAL BERING SEA...

A DEVELOPING PACIFIC LOW WILL MOVE TO 48N 175E TUE AFTERNOON AT 990
MB AND THEN RAPIDLY STRENGTHEN TO 944 MB AS IT MOVES TO 55N 179W
WED AFTERNOON. THE LOW WILL THEN MOVE TO 59 N 172 W AT 943 MB ON
THU MORNING.

$$

PKZ411-060300-
BERING SEA OFFSHORE WEST OF 180 AND EAST OF THE INTERNATIONAL
DATELINE
400 AM AKDT TUE APR 5 2011

...STORM WARNING WEDNESDAY...

.TODAY...E WIND 30 KT EXCEPT SE WIND 10 TO 20 KT S OF 56N. SEAS 14
FT. FREEZING SPRAY N OF 57N. 
.TONIGHT...NE WIND 30 TO 40 KT. SEAS 14 FT. SNOW AND RAIN. FREEZING
SPRAY N OF 57N.
.WED...N WIND 40 KT INCREASING TO 55 KT IN THE AFTERNOON. SEAS 19 TO
23 FT. SNOW AND RAIN. FREEZING SPRAY N OF 57N. 
.WED NIGHT...N WIND 55 KT. SEAS 26 FT. 
.THU...NW WIND 50 KT. SEAS 26 FT. 
.FRI...SW WIND 40 KT. SEAS 15 FT. 
.SAT...W WIND 35 KT. SEAS 15 FT.  

$$

PKZ412-060300-
BERING SEA OFFSHORE 171W TO 180 AND NORTH OF 56N
400 AM AKDT TUE APR 5 2011

...STORM WARNING WEDNESDAY...
...HEAVY FREEZING SPRAY WARNING TONIGHT...

.TODAY...E WIND 15 TO 25 KT. SEAS 11 TO 15 FT. FREEZING SPRAY. 
.TONIGHT...E WIND 30 KT INCREASING TO 45 KT AFTER MIDNIGHT. SEAS
11 FT BUILDING TO 16 FT AFTER MIDNIGHT. SNOW AND RAIN. HEAVY
FREEZING SPRAY NEAR THE ICE EDGE. 
.WED...E WIND 50 TO 60 KT. SEAS 23 FT. RAIN AND SNOW. FREEZING SPRAY
N OF 58N. 
.WED NIGHT...NE WIND 55 KT. SEAS 24 FT. 
.THU...NW WIND 55 KT. SEAS 27 FT. 
.FRI...NW WIND 45 KT. SEAS 22 FT. 
.SAT...S WIND 30 KT. SEAS 10 FT.  

$$

PKZ413-060300-
BERING SEA OFFSHORE 171W TO 180 AND SOUTH OF 56N
400 AM AKDT TUE APR 5 2011

...STORM WARNING WEDNESDAY...

.TODAY...NW WIND 25 KT BECOMING E 30 KT IN THE AFTERNOON. SEAS
13 TO 18 FT. SNOW AND RAIN. 
.TONIGHT...E WIND 35 TO 45 KT. SEAS 15 FT. RAIN AND SNOW. 
.WED...SE WIND 35 TO 45 KT BECOMING S 50 KT IN THE AFTERNOON. SEAS 15
TO 20 FT. RAIN SHOWERS. 
.WED NIGHT...W WIND 60 KT. SEAS 26 FT. 
.THU...NW WIND 55 KT. SEAS 28 FT. 
.FRI...W WIND 40 KT. SEAS 25 FT. 
.SAT...SW WIND 35 KT. SEAS 14 FT.  

$$

PKZ414-060300-
BERING SEA OFFSHORE EAST OF 171W
400 AM AKDT TUE APR 5 2011

...STORM WARNING WEDNESDAY...

.TODAY...NW WIND 30 KT BECOMING NE 20 KT IN THE AFTERNOON. SEAS IN
ICE FREE WATERS 17 FT. SNOW. FREEZING SPRAY N OF 56N. 
.TONIGHT...E WIND 20 KT INCREASING TO 30 TO 40 KT AFTER MIDNIGHT.
SEAS IN ICE FREE WATERS 12 FT. SNOW AND RAIN. FREEZING SPRAY N OF
56N. 
.WED...SE WIND 40 TO 50 KT. SEAS IN ICE FREE WATERS 13 FT BUILDING TO
18 FT IN THE AFTERNOON. RAIN AND SNOW. 
.WED NIGHT...S WIND 60 KT. SEAS IN ICE FREE WATERS 28 FT. 
.THU...W WIND 55 KT. SEAS IN ICE FREE WATERS 32 FT. 
.FRI...NW WIND 45 KT. SEAS IN ICE FREE WATERS 25 FT. 
.SAT...SW WIND 30 KT. SEAS IN ICE FREE WATERS 12 FT.  

$$

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
135 PM AKDT MON APR 4 2011

.ANALYSIS AND UPPER LEVELS...PROGRESSIVE UPPER LEVEL FLOW IS
RESULTING IN RAPIDLY CHANGING WEATHER ACROSS THE FORECAST AREA.
WHILE ONE MATURE LOW EXITS TO THE EASTERN GULF A 120KT+ SUBTROPICAL
JET ALONG AND SOUTH OF THE ALEUTIANS IS PUSHING EVERYTHING QUICKLY
EASTWARD. A VERY WEAK TROUGH EXTENDING FROM THE KUSKOKWIM VALLEY
TO WESTERN GULF IS WEAKENING AS IT LIFTS NORTHEASTWARD OVER TOP
OF A SHORT-WAVE RIDGE. THERE IS JUST ENOUGH VERTICAL MOTION WITH
THIS TROUGH TO PRODUCE SOME LIGHT RAIN AND SNOW ACROSS PORTIONS OF
SOUTHCENTRAL ALASKA. AT THE SURFACE THERE IS A WEAK LOW OVER
INTERIOR ALASKA AND A BUILDING RIDGE ALONG THE NORTH GULF COAST.
THIS IS PRODUCING LOCALIZED SOUTHEAST WINDS WHICH WILL HELP LIMIT
PRECIPITATION REACHING THE GROUND ON THE LEE SIDE OF THE MOUNTAINS.

OUT WEST IS AN ELONGATED UPPER LOW OVER THE BERING SEA WITH A
SHORT-WAVE OVER THE EASTERN BERING RAPIDLY TRACKING TOWARD
SOUTHWEST ALASKA. AT THE SURFACE THERE IS A CORRESPONDING COLD
OCCLUSION WITH STRONG WINDS AND MORE UNSTABLE CONDITIONS BEHIND
THE FRONT.

.MODEL DISCUSSION...NAM IS A LITTLE FASTER WITH MOVEMENT OF
UPPER TROUGH CURRENTLY OVER EASTERN BERING AS IT REACHES
SOUTHCENTRAL EARLY TUESDAY MORNING. THIS WILL AFFECT TIMING OF
WHAT IS EXPECTED TO BE A QUICK SHOT OF SNOW IN ANCHORAGE AND
VICINITY...WITH THE DIFFERENCE BEING EITHER BEFORE OR DURING
THE EARLY MORNING RUSH HOUR TRAFFIC. WILL EVALUATE 18Z RUNS
BEFORE FINALIZING TIMING. NAM IS ALSO AN OUTLIER WITH SPEED OF
MAJOR PACIFIC LOW TUESDAY NIGHT THROUGH THURSDAY SO PREFER AVERAGE
POSITION OF GFS/ECMWF. OTHERWISE...MODELS ARE IN GOOD AGREEMENT
THE NEXT FEW DAYS...ESPECIALLY CONSIDERING THAT TIMING IS USUALLY
A PROBLEM IN THESE FAST FLOW SCENARIOS.

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...AS UPPER LEVEL SHORT-WAVE RIDGE MOVES OVERHEAD
THIS AFTERNOON THE SURFACE RIDGE ALONG THE NORTH GULF COAST WILL
STRENGTHEN AND SOUTHEAST FLOW ACROSS THE COASTAL RANGE WILL INCREASE.
THIS WILL PRODUCE STRONGER DOWNSLOPE WINDS AND DRY OUT THE LEE SIDE
OF THE MOUNTAINS INCLUDING ANCHORAGE. THE BERING SEA TROUGH WILL
BECOME NEGATIVELY TILTED AND SLOW DOWN AS IT MOVES INTO SOUTHCENTRAL
OVERNIGHT. EXPECT PRECIPITATION TO FORM AHEAD OF IT BUT THE SOUTHEAST
FLOW WILL KEEP THINGS MOSTLY DRY FROM ANCHORAGE TO THE MAT-SU UNTIL
THE TROUGH IS RIGHT OVERHEAD. THERE IS SOME UNCERTAINTY ABOUT WHETHER
THIS FIRST TROUGH REACHES ANCHORAGE. LOOKS TO BE CLOSE ENOUGH TO
PRODUCE A QUICK SHOT OF PRECIPITATION IN THE EARLY MORNING. SURFACE
TEMPERATURES ARE FAIRLY WARM RIGHT NOW SO EVEN WITH SLIGHT COOLING
ALOFT PRECIP-TYPE COULD INITIALLY BE A MIX OF RAIN AND SNOW. IN ANY
CASE...ANY SNOW ACCUMULATION THAT DOES OCCUR WILL BE LIGHT. CHANCE
OF PRECIPITATION WILL INCREASE THROUGH THE DAY WEDNESDAY AS A SECOND
TROUGH CATCHES UP TO THE FIRST AND COLD ADVECTION ENSUES. SURFACE
LOW OVER WEST PRINCE WILLIAM SOUND WILL ALSO PROVIDE SOME MOISTURE
ADVECTION. THEREFORE...PLAN ON INCREASING POPS AND ADDING
IN SNOW ACCUMULATION FOR LATE TUESDAY THROUGH WEDNESDAY MORNING.
THIS SYSTEM HAS THE POTENTIAL TO PRODUCE SEVERAL INCHES OF SNOW
FROM THE KENAI PENINSULA TO ANCHORAGE AND THE MAT-SU. HOWEVER...THE
DETAILS OF THE UPPER LEVELS ARE STILL IN QUESTION SO WILL BE
CONSERVATIVE WITH AMOUNTS UNTIL CONFIDENCE IN A GIVEN SOLUTION
INCREASES. CONDITIONS WILL DRY OUT WEDNESDAY BEHIND THE TROUGH...BUT
FRONT ASSOCIATED WITH A VERY STRONG BERING SYSTEM WILL ARRIVE BY
THURSDAY.

SOUTHWEST ALASKA...AS SURFACE FRONT AND UPPER TROUGH MOVE ONSHORE
THIS AFTERNOON AND EVENING SNOW WILL SPREAD INLAND. COLD ADVECTION
COMBINED WITH A SECONDARY TROUGH DROPPING DOWN FROM THE NORTH ON
TUESDAY WILL PRODUCE SNOW SHOWERS AND GUSTY WINDS...ESPECIALLY
ALONG THE COAST. AFTER A BREAK LATE TUESDAY NIGHT INTO WEDNESDAY
RAPIDLY INTENSIFYING LOW WILL MOVE INTO BERING WITH A STRONG FRONT
LIKELY IMPACTING THE SOUTHWEST COAST BY WEDNESDAY AFTERNOON.
TEMPERATURES SUPPORT ALL SNOW AS PRECIPITATION FIRST BEGINS...BUT
STRONG WARM ADVECTION WILL CHANGE PRECIP TO MOSTLY RAIN WEDNESDAY
NIGHT. THERE COULD BE SOME BRIEF BLOWING SNOW ISSUE IN THE KUSKOKWIM
DELTA AT THE ONSET. AT THIS POINT DON'T THINK IT WILL BE OF A LONG
ENOUGH DURATION TO WARRANT A BLIZZARD BUT WILL RE-EVALUATE THIS AS
WE GET CLOSER TO THE EVENT.

BERING SEA/ALEUTIANS...A WEAK SURFACE LOW OVER THE NORTHWEST
PACIFIC WILL RAPIDLY INTENSIFY TUESDAY WITH AN AMPLIFYING UPPER
TROUGH AND STRONG UPPER DIVERGENCE BETWEEN TWO JET STREAKS. THIS
WILL BE A VERY LARGE SYSTEM...AFFECTING THE ENTIRE BERING SEA
REGION BY WEDNESDAY AFTERNOON. PLAN TO MAX WINDS OUT AT STORM FORCE
FOR NOW BUT IF MODELS ARE CONSISTENT IN NEXT MODEL CYCLE WILL HAVE
TO INCREASE SOME AREAS TO HURRICANE FORCE AND CONSIDER ISSUING HIGH
WIND WATCHES OR BLIZZARD WATCHES ALONG THE ALEUTIANS. LOTS OF ARCTIC
AIR WILL FEED IN BEHIND THE SYSTEM AS IT TRACKS TOWARD THE BERING
STRAIT LATE IN THE WEEK. THUS...STRONG WINDS AND SNOW SHOWERS WILL
DOMINATE FOR A FEW DAYS.

.LONG TERM FORECAST...MAJOR STORM IN THE BERING MID WEEK WILL
CONTINUE TO AFFECT MUCH OF ALASKA ALL THE WAY INTO THE WEEKEND.
LOOKS LIKE UPPER LEVEL PROGRESSIVE PATTERN WILL CONTINUE AFTER
THIS WITH ANOTHER STORM MOVING IN FROM THE NORTHWEST PACIFIC
LATE IN THE WEEK.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE WARNING...130 132 150 155 160 165 170 171 172 175
                        176 179 180.
         HEAVY FREEZING SPRAY WARNING...160 165 185.
FIRE WEATHER...NONE.

SEB APR 11