Storm Warning 24, NWS Anchorage, AK

603 
FZAK62 PAFC 061256
OFFALU

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 AM AKST WED FEB 6 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.

PKZ499-070300-
400 AM AKST WED FEB 6 2013
.SYNOPSIS FOR CENTRAL BERING SEA...

A 952 MB LOW NEAR 49N 175E WILL MOVE TO NEAR 50N 171W AT 980 MB EARLY
FRI MORNING. AN ASSOCIATED FRONT OVER THE WESTERN TO CENTRAL BERING
WILL WEAKEN AS IT TRACKS TO THE EASTERN BERING AND SW ALASKA EARLY
THU. 

$$

PKZ411-070300-
BERING SEA OFFSHORE WEST OF 180 AND EAST OF THE INTERNATIONAL
DATELINE
400 AM AKST WED FEB 6 2013

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

.TODAY...NE WIND 40 TO 50 KT. SEAS 22 TO 28 FT. SNOW AND RAIN. HEAVY
FREEZING SPRAY N OF 58N. 
.TONIGHT...NE WIND 35 TO 50 KT. SEAS 21 TO 27 FT. SNOW AND RAIN.
HEAVY FREEZING SPRAY N OF 57N.
.THU...NE WIND 35 TO 45 KT. SEAS 21 TO 25 FT. SNOW. HEAVY FREEZING
SPRAY N OF 57N.
.THU NIGHT...N WIND 40 KT. SEAS 20 FT. 
.FRI...NE WIND 30 KT. SEAS 15 FT. 
.SAT...E WIND 35 KT. SEAS 13 FT. 
.SUN...E WIND 25 KT. SEAS 15 FT.  

$$

PKZ412-070300-
BERING SEA OFFSHORE 171W TO 180 AND NORTH OF 56N
400 AM AKST WED FEB 6 2013

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

.TODAY...E WIND 35 TO 45 KT. SEAS 14 FT BUILDING TO 19 FT IN THE
AFTERNOON. SNOW. HEAVY FREEZING SPRAY N OF 58N. 
.TONIGHT...NE WIND 30 TO 45 KT. SEAS 15 TO 22 FT. SNOW. HEAVY
FREEZING SPRAY N OF 57N. 
.THU...NE WIND 30 TO 40 KT. SEAS 14 TO 19 FT. SNOW. HEAVY FREEZING
SPRAY N OF 57N. 
.THU NIGHT...NE WIND 40 KT. SEAS 16 FT. 
.FRI...N WIND 35 KT. SEAS 14 FT. 
.SAT...N WIND 35 KT. SEAS 11 FT. 
.SUN...N WIND 20 KT. SEAS 9 FT.  

$$

PKZ413-070300-
BERING SEA OFFSHORE 171W TO 180 AND SOUTH OF 56N
400 AM AKST WED FEB 6 2013

...GALE WARNING TODAY AND THURSDAY...

.TODAY...SE WIND 35 TO 45 KT BECOMING S 25 KT IN THE LATE AFTERNOON.
SEAS 18 FT. RAIN AND SNOW. 
.TONIGHT...SE WIND 15 TO 25 KT. SEAS 14 TO 19 FT. PATCHY FOG. RAIN
AND SNOW. 
.THU...NE WIND 25 TO 35 KT. SEAS 14 TO 18 FT. SNOW.
.THU NIGHT...NE WIND 40 KT. SEAS 18 FT. 
.FRI...N WIND 35 KT. SEAS 16 FT. 
.SAT...NE WIND 35 KT. SEAS 14 FT. 
.SUN...SE WIND 15 KT. SEAS 10 FT.  

$$

PKZ414-070300-
BERING SEA OFFSHORE EAST OF 171W
400 AM AKST WED FEB 6 2013

...GALE WARNING THROUGH TONIGHT...

.TODAY...E WIND 25 TO 35 KT. SEAS IN ICE FREE WATERS 9 TO 12 FT. SNOW
AND RAIN. FREEZING SPRAY N OF 56N. 
.TONIGHT...E WIND 25 TO 35 KT BECOMING S 25 KT AFTER MIDNIGHT. SEAS
IN ICE FREE WATERS 9 TO 12 FT. PATCHY FOG. SNOW AND RAIN. 
.THU...S WIND 15 TO 25 KT. SEAS IN ICE FREE WATERS 8 FT. PATCHY FOG.
SNOW.
.THU NIGHT...SE WIND 25 KT. SEAS IN ICE FREE WATERS 8 FT. 
.FRI...N WIND 40 KT. SEAS IN ICE FREE WATERS 14 FT. 
.SAT...NW WIND 40 KT. SEAS IN ICE FREE WATERS 15 FT. 
.SUN...W WIND 25 KT. SEAS IN ICE FREE WATERS 6 FT.  

$$

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
1257 PM AKST TUE FEB 5 2013

.ANALYSIS AND UPPER LEVELS...UPPER LEVEL FLOW IS PROGRESSIVE WITH
SYSTEMS MOVING RELATIVELY QUICKLY FROM WEST TO EAST ACROSS THE
FORECAST AREA. SOUTHCENTRAL ALASKA IS QUIET AT THE MOMENT UNDERNEATH
A WEAK SHORT-WAVE RIDGE WITH SOME MID TO HIGH LEVEL CLOUDS PASSING
OVERHEAD AS WELL AS A FEW ISOLATED AREAS OF FOG. A LOW SPINNING SOUTH
OF THE GULF OF ALASKA HAS PUSHED A WEAK FRONT NORTHWESTWARD ACROSS
THE EASTERN GULF. THIS HAS TIGHTENED UP THE PRESSURE GRADIENT ALONG
THE NORTH GULF COAST JUST ENOUGH TO PRODUCE SOME LOCALIZED GAP WINDS
IN THE USUAL PLACES.

LOOKING UPSTREAM...AN UPPER LEVEL LOW AND SHARP SHORT-WAVE ARE
MAKING THERE WAY ACROSS SOUTHWEST ALASKA PRODUCING AREAS OF
SNOW...WITH RAIN ALONG THE NORTHERN ALASKA PENINSULA. WITH LIGHT
WINDS AND A STABLE AIRMASS (AS SCENE IN THE BETHEL AND MCGRATH
SOUNDINGS) AREAS OF FOG AND STRATUS HAVE ALSO DEVELOPED ACROSS THE
REGION.

MEANWHILE A VERY LARGE AND STRONG LOW SOUTH OF THE ALEUTIANS HAS
BOTTOMED OUT AROUND 950 MB AND IS REALLY BEGINNING TO WRAP UP. THE
OCCLUDED FRONT IS SPREADING NORTH AND EASTWARD TOWARD THE ALEUTIANS.

.MODEL DISCUSSION...THE 12Z NAM WAS QUITE A BIT FARTHER NORTH THAN
OTHER MODELS WITH TRACK OF SHORT-WAVE ACROSS SOUTHCENTRAL TONIGHT
AND WEDNESDAY. 18Z HAS TRENDED SOUTHWARD GIVING MORE CONFIDENCE IN
THE SOUTHERN SOLUTION. MODELS SHOW GOOD AGREEMENT WITH HANDLING OF
THE SYSTEM SOUTH OF THE ALEUTIANS THROUGH ABOUT THURSDAY MORNING.
DIFFERENCES ARISE AS THE TRIPLE POINT MOVES INTO THE WESTERN GULF
ON THURSDAY. THE WESTERN MOST SOLUTIONS (NAM/ECMWF) TRACK THE TRIPLE
POINT TO NEAR THE BARREN ISLANDS WHICH WOULD PRODUCE STRONG
DOWNSLOPING WINDS AND WARMER TEMPERATURES FOR THE WESTERN
KENAI/ANCHORAGE/MAT VALLEY. THE EASTERN MOST SOLUTION (GFS) TRACKS
THE TRIPLE POINT INTO THE NORTHERN GULF WHICH WOULD MEAN WEAKER
DOWNSLOPING WINDS AND COLDER TEMPERATURES. FOR THE TIME BEING WILL
GO WITH AN INTERMEDIATE SOLUTION UNTIL GAIN MORE CONFIDENCE IN WHERE
THIS TRIPLE POINT WILL TRACK.

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...EXPECT LOCALIZED GAP WINDS ALONG THE NORTH
GULF COAST TO DISSIPATE THIS EVENING AS THE LOW SOUTH OF THE GULF
EXITS TO THE SOUTH. SNOW WILL DEVELOP EARLY TOMORROW MORNING ALONG
THE COOK INLET TO SUSITNA VALLEY CORRIDOR AS THE TROUGH OVER
SOUTHWEST ALASKA ARRIVES. THE TROUGH IS FAIRLY SHARP AND ACCOMPANIED
BY LOW LEVEL COLD ADVECTION. HOWEVER IT WILL BE PROGRESSING EASTWARD
FAIRLY FAST WHICH WILL LIMIT SNOW ACCUMULATION. OBSERVATIONS OVER
SOUTHWEST ALASKA TODAY INDICATE 2 TO 3 INCHES OF SNOW. EXPECT
SIMILAR AMOUNTS AS THE TROUGH CROSSES SOUTHCENTRAL WITH ISOLATED
HIGHER AMOUNTS ALONG THE WEST SIDE OF THE MOUNTAINS THANKS TO WEAK
UPSLOPE FLOW. THIS TROUGH WILL QUICKLY EXIT WEDNESDAY NIGHT AS A
SHORT-WAVE RIDGE MOVES IN. THIS WILL BE CONDUCIVE TO FORMATION OF
AREAS OF FOG. HOWEVER FRONTAL SYSTEM WILL QUICKLY MOVE IN FROM THE
BERING ON THURSDAY BRINGING PRECIP BACK INTO THE AREA. EVEN WITH
POTENTIAL FOR DOWNSLOPING WINDS...MODELS INDICATE UPPER FLOW WILL
BE SOUTHERLY...SO STILL EXPECT SOME PRECIP IN THE TYPICAL DOWNSLOPE
AREAS. AS MENTIONED IN THE MODEL DISCUSSION THERE IS SOME UNCERTAINTY
WITH THE PLACEMENT OF THE TRIPLE POINT WHICH WILL AFFECT EXTENT OF
DOWNSLOPING WINDS...TEMPERATURES...AMOUNT OF PRECIP...AND
PRECIP-TYPE.

SOUTHWEST ALASKA...UPPER TROUGH WILL CONTINUE EASTWARD ACROSS
SOUTHWEST ALASKA TONIGHT. COLDER AIR WILL MOVE IN THIS AFTERNOON
AND CHANGE PRECIP TO ALL SNOW ALONG THE NORTHERN ALASKA PENINSULA.
PRECIP WILL END FROM WEST TO EAST AS THE TROUGH MOVES TO SOUTHCENTRAL
ON WEDNESDAY. THE COMPLETE LOSS OF MID AND UPPER LEVEL MOISTURE
BEHIND THE TROUGH COMBINED WITH VERY MOIST LOW LEVELS WILL LEAD
TO WIDESPREAD AREAS OF STRATUS AND FOG. THESE AREAS OF LOW CLOUDS
AND FOG WILL PERSIST UNTIL THE FRONT EXTENDING FROM THE ALEUTIAN
LOW ARRIVES WEDNESDAY NIGHT INTO THURSDAY. THE FRONT WILL BE
WEAKENING AS IT ARRIVES...BUT WINDS MAY BE STRONG ENOUGH TO PRODUCE
SOME BLOWING SNOW ISSUES ALONG THE KUSKOKWIM DELTA. TRIPLE POINT WILL
TRACK ALONG THE ALASKA PENINSULA WHICH MEANS AIRMASS WILL STAY COLD
ENOUGH FOR ALL SNOW WITH THE POSSIBLE EXCEPTION OF THE NORTHERN
ALASKA PENINSULA/ALEUTIAN RANGE.

BERING SEA/ALEUTIANS...THE GREATEST IMPACT FROM THE ALEUTIAN LOW
WILL BE WIDESPREAD GALE TO STORM FORCE WINDS AS THE FRONTAL SYSTEM
SLOWLY PROGRESSES NORTH AND EASTWARD. WARMER AIR WILL ACCOMPANY THE
OCCLUSION AND RESULT IN PRIMARILY RAIN ALONG THE ALEUTIANS AND
SOUTHERN ALASKA PENINSULA. THE PRIBILOFS HOWEVER WILL REMAIN ON THE
COLD SIDE OF THE FRONT. EVEN THOUGH EASTERLY FLOW IS NOT THE MOST
FAVORABLE FOR BLIZZARD CONDITIONS...SURFACE TEMPERATURES WILL REMAIN
IN THE 20S AND PRECIPITATION WILL BE FAIRLY HEAVY AS THE MAIN
PRE-FRONTAL BAND MOVES THROUGH WEDNESDAY AFTERNOON AND EVENING.
THE PRESENCE OF SEA ICE IN THE VICINITY CAN ALSO CONTRIBUTE TO LESS
OF A MARINE INFLUENCE...HELPING MAINTAIN COLDER AND DRIER CONDITIONS
WHICH ARE MORE FAVORABLE FOR BLOWING SNOW. THEREFORE...WILL ISSUE A
BLIZZARD WARNING WITH THE AFTERNOON PACKAGE.

.LONG TERM FORECAST...THE ALEUTIAN STORM SYSTEM WHICH WILL AFFECT
MOST OF THE FORECAST AREA AS OCCLUDED FRONT TRACKS TO SOUTHCENTRAL
THURSDAY...WILL QUICKLY WEAKEN ON FRIDAY. MODELS ARE IN FAIRLY GOOD
AGREEMENT ON THE SYNOPTIC EVOLUTION AFTER THIS POINT WITH TWO MAJOR
LOWS MOVING INTO THE REGION...ONE OVER THE NORTHWEST
PACIFIC/ALEUTIANS AND ANOTHER MOVING FROM THE PACIFIC NORTHWARD TO
THE MAINLAND.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...STORM WARNING...172 175 176.
         GALE WARNING...160 170 171 179 180 185.
FIRE WEATHER...NONE.

SERB FEB 13