Gale Warning 140, NWS Anchorage, AK

385 
FZAK62 PAFC 280034
OFFALU

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 PM AKST WED FEB 27 2013

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.

PKZ499-281500-
400 PM AKST WED FEB 27 2013
.SYNOPSIS FOR CENTRAL BERING SEA...
A 983 MB LOW NEAR 51N 163W WILL WEAKEN AS MOVES INTO THE NORTHEAST
PACIFIC THU NIGHT. A 1009 MB LOW WILL FORM NEAR 53N 175E WED
EVENING AND MOVE TO 55N 178W THU EVENING BEFORE DISSIPATING OVER 
THE CENTRAL BERING FRI MORNING. A DEVELOPING LOW WILL RAPIDLY
INTENSIFY TO 972 MB AND MOVE TO 50N 176W FRI AFTERNOON.
$$

PKZ411-281500-
BERING SEA OFFSHORE WEST OF 180 AND EAST OF THE INTERNATIONAL
DATELINE
400 PM AKST WED FEB 27 2013

...HEAVY FREEZING SPRAY WARNING THROUGH THURSDAY NIGHT...

.TONIGHT...NW WIND 15 TO 25 KT. SEAS 8 FT. HEAVY FREEZING SPRAY. 
.THU...N OF 56N...W WIND 25 KT. S OF 56N...N WIND 15 TO 25 KT.  SEAS
7 FT. SNOW SHOWERS. HEAVY FREEZING SPRAY.
.THU NIGHT...N OF 56N...W WIND 15 KT. S OF 56N...N WIND 15 TO 25 KT.
SEAS 7 FT. SNOW SHOWERS. HEAVY FREEZING SPRAY. 
.FRI...N OF 56N...N WIND 15 TO 25 KT. S OF 56N...N WIND INCREASING TO
30 TO 40 KT BY AFTERNOON. SEAS 10 FT. 
.FRI NIGHT...N WIND 30 TO 40 KT. SEAS 16 FT. 
.SAT...N WIND 40 KT. SEAS 15 FT. 
.SUN...SE WIND 35 KT. SEAS 15 FT. 
.MON...S WIND 30 KT. SEAS 17 FT.  

$$

PKZ412-281500-
BERING SEA OFFSHORE 171W TO 180 AND NORTH OF 56N
400 PM AKST WED FEB 27 2013

...HEAVY FREEZING SPRAY WARNING THROUGH THURSDAY NIGHT...

.TONIGHT...NW WIND 20 TO 30 KT. SEAS 8 FT. HEAVY FREEZING SPRAY. 
.THU...NW WIND 10 TO 20 KT. SEAS 6 FT. HEAVY FREEZING SPRAY. 
.THU NIGHT...W WIND 15 KT BECOMING VARIABLE 10 TO 20 KT AFTER
MIDNIGHT. SEAS 5 FT. HEAVY FREEZING SPRAY. 
.FRI...NE TO SE WIND 20 TO 30 KT. SEAS 8 FT. 
.FRI NIGHT...NE WIND 40 KT. SEAS 17 FT. 
.SAT...N WIND 35 KT. SEAS 15 FT. 
.SUN...SE WIND 35 KT. SEAS 12 FT. 
.MON...S WIND 30 KT. SEAS 14 FT.  

$$

PKZ413-281500-
BERING SEA OFFSHORE 171W TO 180 AND SOUTH OF 56N
400 PM AKST WED FEB 27 2013

...GALE WARNING TONIGHT...

.TONIGHT...N WIND 25 TO 35 KT. SEAS 12 FT. FREEZING SPRAY. 
.THU...NW WIND 15 TO 25 KT BECOMING VARIABLE 15 KT IN THE AFTERNOON.
SEAS 8 FT. FREEZING SPRAY. 
.THU NIGHT...VARIABLE WIND 15 KT BECOMING S 15 TO 25 KT AFTER
MIDNIGHT. SEAS 7 FT. SNOW. FREEZING SPRAY. 
.FRI...SE WIND 25 KT INCREASING TO E 45 KT IN THE AFTERNOON. SEAS 15
FT. 
.FRI NIGHT...NE WIND 45 KT. SEAS 21 FT. 
.SAT...NW WIND 45 KT. SEAS 21 FT. 
.SUN...S WIND 35 KT. SEAS 13 FT. 
.MON...S WIND 30 KT. SEAS 16 FT.  

$$

PKZ414-281500-
BERING SEA OFFSHORE EAST OF 171W
400 PM AKST WED FEB 27 2013

...GALE WARNING TONIGHT...
...HEAVY FREEZING SPRAY WARNING THROUGH THURSDAY...

.TONIGHT...N WIND 25 TO 35 KT. SEAS IN ICE FREE WATERS 10 FT. SNOW
SHOWERS. HEAVY FREEZING SPRAY. 
.THU...N WIND 30 KT. SEAS IN ICE FREE WATERS 9 FT. HEAVY FREEZING
SPRAY. 
.THU NIGHT...N WIND 15 TO 25 KT BECOMING SE 20 KT AFTER MIDNIGHT. 
SEAS IN ICE FREE WATERS 4 FT. FREEZING SPRAY. 
.FRI...SE WIND 25 KT INCREASING TO 40 KT IN THE AFTERNOON. SEAS IN
ICE FREE WATERS 10 FT. 
.FRI NIGHT...SE WIND 45 KT. SEAS IN ICE FREE WATERS 17 FT. 
.SAT...E WIND 35 KT. SEAS IN ICE FREE WATERS 14 FT. 
.SUN THROUGH MON...SE WIND 35 KT. SEAS IN ICE FREE WATERS 11 FT. 

$$

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
1245 PM AKST TUE FEB 26 2013

.ANALYSIS AND UPPER LEVELS...THE RAPID PACE OF STORM SYSTEMS ACROSS
THE SOUTHERN TIER OF ALASKA HAS SLOWED SIGNIFICANTLY WITH DEVELOPMENT
OF CLOSED CIRCULATIONS IN THE UPPER LEVELS AND THE UPPER JET SINKING
SOUTHWARD ACROSS THE NORTH PACIFIC. ONE LOW COMPLEX IN THE GULF
CONTINUES TO PRODUCE GALE TO STORM FORCE WINDS OVER THE NORTHERN
GULF. THE BULK OF PRECIP IS OFFSHORE THANKS TO A (DRY) OFFSHORE
COMPONENT TO THE LOW LEVEL FLOW ACROSS SOUTHCENTRAL. TO THE WEST OF
THE GULF LOW A SHORT-WAVE TROUGH OVER THE EASTERN BERING IS LIFTING
NORTHWARD TOWARD SOUTHWEST ALASKA CONTRIBUTING TO AREAS OF LIGHT
SNOW OVER BRISTOL BAY AND THE KUSKOKWIM DELTA. THE KUSKOKWIM DELTA
IS OBSERVING PERIODS OF LOW VISIBILITIES IN BLOWING SNOW WITH STRONG
NORTHERLY WINDS...ESPECIALLY ALONG THE COAST. THE OTHER LOW COMPLEX
IS TRACKING SLOWLY EASTWARD JUST SOUTH THE ALEUTIAN CHAIN. THIS IS
A MATURE LOW WHICH HAS BEGUN TO FILL AND WHICH IS CAUSING ONLY
MINOR IMPACTS ALONG THE ALEUTIANS.

.MODEL DISCUSSION...MODELS ARE VERIFYING FAIRLY WELL WITH CURRENT
SYSTEMS. AS ALEUTIAN LOW AND TROUGH APPROACH THE GULF EXPECT
CYCLOGENESIS OVER THE NORTHEAST PACIFIC INITIATED BY UPPER LEVEL
WAVES CROSSING THE NORTH PACIFIC IN THE BASE OF THE LONG-WAVE
TROUGH. MODELS ARE REALLY STRUGGLING WITH INTENSITY AND TRACK OF
THESE LOWS AND DISPLAY VERY POOR RUN-TO-RUN CONTINUITY. FOR NOW
PREFER A MIDDLE OF THE PACK SOLUTION AS REPRESENTED BY THE ECMWF.

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...THE UPPER LOW OVER THE GULF WILL OPEN INTO
A TROUGH AND LIFT NORTHWESTWARD ACROSS SOUTHCENTRAL WEDNESDAY.
THIS WILL PUSH PRECIP BACK ONSHORE ALONG THE COASTAL ZONE WHILE
INLAND AREAS WILL REMAIN MOSTLY DRY. WITH A BRIEF PERIOD OF STRONGER
WINDS AS THIS MOVES ONSHORE EXPECT A PERIOD OF LOW VISIBILITIES IN
BLOWING SNOW THROUGH THOMPSON PASS. DOESN'T LOOK LIKE QUITE ENOUGH
WIND FOR A BLIZZARD SO WILL ISSUE A WINTER WEATHER ADVISORY FOR
BLOWING SNOW. MEANWHILE...THE SURFACE LOW WILL WEAKEN AS IT TRACKS
WESTWARD TO KODIAK ISLAND AND THEN DISSIPATE A SIT TRIES TO CROSS
OVER TO BRISTOL BAY. THE MAIN IMPACT OF THIS WILL BE TO INCREASE
THE EAST-WEST PRESSURE GRADIENT ALONG TURNAGAIN ARM AND PRODUCE
TO STRONG WINDS ON THE WEST SIDE OF THE ARM. THERE IS SOME
UNCERTAINTY IN THE TRACK OF THE NEXT COUPLE SYSTEMS MOVING INTO
THE GULF THIS WEEK...BUT THE RESULT WILL BE THE SAME AS THE CURRENT
SYSTEM WITH THE BULK OF WIND AND PRECIP REMAINING ALONG THE GULF
COAST.

SOUTHWEST ALASKA...AS GULF LOW BEGINS TO OPEN INTO A TROUGH THIS
EVENING A SHORT-WAVE WILL SPIN OFF FROM IT AND HEAD NORTHWEST
ACROSS SOUTHWEST ALASKA. THIS WILL BRING ANOTHER ROUND OF SNOW
TO THE KUSKOKWIM DELTA. A WINTER WEATHER ADVISORY FOR BLOWING
SNOW IS IN  EFFECT THROUGH MIDNIGHT. A SERIES OF WEAK UPPER LEVEL
WAVES WILL CONTINUE TO TRANSIT SOUTHWEST ALASKA AS GULF TROUGH
LIFTS NORTHWESTWARD TONIGHT AND WEDNESDAY. WITH WEAK AND UNFOCUSED
VERTICAL MOTION SNOWFALL WILL BE SPOTTY ACROSS THE REGION. AS WE
HEAD THROUGH THE REMAINDER OF THE WEEK THE FOCUS WILL SHIFT TO
SYSTEMS TRACKING INTO THE GULF WHILE HIGH PRESSURE BUILDS FROM
THE CENTRAL BERING SEA TOWARD SOUTHWEST ALASKA. THIS WILL PRODUCE
COLD AND DRY CONDITIONS ACROSS THE REGION.

BERING SEA/ALEUTIANS...THE ALEUTIANS WILL SEE A BRIEF BREAK AS
THE CURRENT SYSTEM EXITS TO THE EAST TONIGHT AND WEDNESDAY BEFORE
ANOTHER DEEP LOW ARRIVES THURSDAY NIGHT AND FRIDAY. THIS NEXT SYSTEM
WILL BE INTENSIFYING AS IT REACHES THE ALEUTIANS AND WILL QUITE A
BIT MORE POWERFUL THAN THE CURRENT SYSTEM. THERE IS GOOD POTENTIAL
THAT WIND WARNINGS AND OR/BLIZZARD THRESHOLDS MAY BE REACHED...BUT
IT IS TOO EARLY TO ISSUE ANYTHING QUITE YET. MEANWHILE...THE TROUGH
CURRENTLY OVER THE EASTERN BERING WILL ROTATE BACK WESTWARD TONIGHT
THROUGH WEDNESDAY NIGHT BRINGING SOME SNOW TO THE PRIBILOF ISLANDS.
WINDS ARE BORDERLINE FOR A BLIZZARD...SO CURRENTLY LEANING TOWARD
ISSUING A WINTER WEATHER ADVISORY FOR BLOWING SNOW.

.LONG TERM FORECAST...UPPER LEVEL FLOW WILL UNDERGO AMPLIFICATION
BY THE END OF THE WEEK BUT REMAIN PROGRESSIVE. THUS THE STORM TRACK
WILL BE SIMILAR TO THE CURRENT TRACK FROM THE ALEUTIANS TO THE
GULF/NORTHEAST PACIFIC. MORE SPECIFICALLY THE MAJOR STORM MOVING
TO THE ALEUTIANS ON FRIDAY WILL TRACK TO THE SOUTHERN GULF AND
NORTHEAST PACIFIC NEXT WEEKEND...POSSIBLY REMAINING FAR ENOUGH
SOUTH TO MISS SOUTHCENTRAL ALASKA COMPLETELY. MODELS INDICATE
SYSTEM AFTER THIS ONE TAKING A MORE NORTHERLY TRACK INTO THE BERING
WITH RIDGE BUILDING DOWNSTREAM OVER MAINLAND ALASKA. THUS...COULD
BE HEADED INTO A MORE PROLONGED DRY PERIOD OVER MAINLAND ALASKA.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WATCH 195.
MARINE...GALE WARNING...120 130 141 172 175.
         HEAVY FREEZING SPRAY WARNING...179.
FIRE WEATHER...NONE.

SEB FEB 13