Gale Warning 632, NWS Anchorage, AK

397 
FZAK61 PAFC 162328
OFFAER

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 PM AKDT TUE OCT 16 2012

OFFSHORE WATERS FORECAST FOR THE GULF OF ALASKA WEST OF 144W

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.

PKZ399-171500-
400 PM AKDT TUE OCT 16 2012
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A 986 MB LOW NEAR 60N 148W WILL BE A 995 MB LOW AT 58N 144W BY WED
AFTERNOON AND A 1002 MB LOW AT 58N 139W BY THU AFTERNOON. 

$$

PKZ351-171500-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W
400 PM AKDT TUE OCT 16 2012

.TONIGHT...SW WIND 30 KT. SEAS 15 FT. RAIN SHOWERS. 
.WED...SW WIND 30 KT BECOMING NW 25 KT IN THE AFTERNOON. SEAS 10 FT.
.WED NIGHT AND THU...NW WIND 25 KT. SEAS 8 FT. 
.THU NIGHT...N WIND 15 KT. SEAS 5 FT. 
.FRI AND SAT...N WIND 20 KT. SEAS 6 FT. 
.SUN...N WIND 15 KT. SEAS 5 FT.  

$$

PKZ352-171500-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W
400 PM AKDT TUE OCT 16 2012

...GALE WARNING TONIGHT...

.TONIGHT...W WIND 35 KT. SEAS 15 FT. 
.WED...W WIND 30 KT. SEAS 11 FT. 
.WED NIGHT AND THU...NW WIND 30 KT. SEAS 10 FT. 
.THU NIGHT AND FRI...NW WIND 25 KT. SEAS 7 FT. 
.SAT AND SUN...N WIND 20 KT. SEAS 7 FT. 

$$

755 
FZAK61 PAFC 171125
OFFAER

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 AM AKDT WED OCT 17 2012

OFFSHORE WATERS FORECAST FOR THE GULF OF ALASKA WEST OF 144W

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.

PKZ399-180300-
400 AM AKDT WED OCT 17 2012
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 997 MB LOW NEAR 59N 148W WILL MOVE TO 58N 141W AT 1000 MB LATE WED
NIGHT AND WILL CONTINUE WEAKENING AS IT DRIFTS TOWARDS THE PANHANDLE
LATE THU NIGHT. 

$$

PKZ351-180300-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W
400 AM AKDT WED OCT 17 2012

.TODAY...SW WIND 30 KT BECOMING NW 25 KT IN THE AFTERNOON. SEAS 11
FT. 
.TONIGHT...NW WIND 30 KT. SEAS 11 FT. 
.THU...NW WIND 25 KT. SEAS 9 FT. 
.THU NIGHT...NW WIND 15 KT. SEAS 6 FT. 
.FRI AND SAT...N WIND 20 KT. SEAS 6 FT.  
.SUN...N WIND 15 KT. SEAS 5 FT.  

$$

PKZ352-180300-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W
400 AM AKDT WED OCT 17 2012

.TODAY...W WIND 30 KT. SEAS 11 FT. 
.TONIGHT AND THU...NW WIND 30 KT. SEAS 11 FT. 
.THU NIGHT AND FRI...NW WIND 25 KT. SEAS 8 FT. 
.SAT...N WIND 25 KT. SEAS 8 FT. 
.SUN...N WIND 15 KT. SEAS 6 FT.  

$$

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
1210 PM AKDT MON OCT 15 2012

.ANALYSIS AND UPPER LEVELS...A HIGH AMPLITUDE PATTERN IS IN PLACE
WITH A TROUGH CENTERED OVER MAINLAND ALASKA AND A RIDGE OVER THE
FAR WESTERN BERING SEA. A POLAR JET BETWEEN THE TWO IS DRIVING
COLDER AIR SOUTHWARD ACROSS THE EASTERN BERING AND SOUTHWEST
ALASKA. THIS IS PRODUCING SNOW SHOWERS AND GUSTY WINDS ACROSS
THE REGION...WITH THE STRONGEST WINDS THROUGH GAPS OF THE ALASKA
PENINSULA. A SHORT-WAVE TROUGH SWINGING THROUGH SOUTHWEST ALASKA
THIS MORNING IS ALSO CONTRIBUTING TO STRONG DOWNWARD MOTION AND
MIXING DOWN OF STRONGER WINDS FROM ALOFT.

A MATURE LOW OVER THE GULF OF ALASKA IS SLOWLY LIFTING NORTHWARD.
A DEFORMATION ZONE HAS SET UP BETWEEN THIS LOW AND THE SHORT-WAVE
TROUGH OVER SOUTHWEST ALASKA RESULTING IN STEADY SNOW ALONG THE
ALASKA AND ALEUTIAN RANGES. EAST OF THIS DEFORMATION ZONE RADAR
AND SATELLITE IMAGERY INDICATE A BROAD UNSTABLE ATMOSPHERE WITH
SHOWERS OVER MUCH OF THE GULF OF ALASKA.

.MODEL DISCUSSION...THERE IS A PRETTY GOOD SPREAD IN MODELS WITH
POSITION OF SURFACE LOW OVER THE GULF AS THE FIRST UPPER LOW
DISSIPATES AND SECOND ONE MOVES IN. DON'T REALLY SEE ANY REASON
TO FAVOR A PARTICULAR SOLUTION AT THIS POINT. THEY AT LEAST ALL
SHOW THE SAME GENERAL TRENDS IN MOVEMENT OF THE LOW AND THE EXACT
POSITION WON'T HAVE A HUGE IMPACT ON THE PRECIPITATION PATTERN.
BIGGEST IMPACT WILL BE ON WINDS OVER THE NORTHERN GULF...SO
FORECAST CONFIDENCE IN THAT AREA IS BELOW AVERAGE.

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...AS LOW OVER THE GULF CONTINUES TO LIFT
NORTHWARD SHOWER COVERAGE WILL INCREASE ALONG THE NORTH GULF
COAST. A FEW OF THESE SHOWERS MAY MAKE IT OVER THE MOUNTAINS
AND INLAND...BUT THEY WILL BE SHORT-LIVED. COLDER AIR FILTERING
IN FROM THE WEST SUPPORTS MAINLY SNOW WITH THE EXCEPTION OF THE
PRINCE WILLIAM SOUND AREA WHICH WILL TAKE LONGER TO COOL DOWN.
AN UPPER LOW DROPPING SOUTHWARD ACROSS SOUTHWEST ALASKA TONIGHT
WILL SWING EASTWARD INTO THE GULF TUESDAY WHICH WILL CAUSE THE
FIRST UPPER LOW TO OPEN INTO A TROUGH AND DISSIPATE. THIS NEW
UPPER LOW WILL THEN QUICKLY TRACK TO THE EASTERN GULF WEDNESDAY
AND THURSDAY WITH COLD DRY CONDITIONS SETTLING IN ACROSS
SOUTHCENTRAL.

MEANWHILE...STRONG WINDS WILL PERSIST OVER THE WESTERN GULF.
UPPER LOW DROPPING ACROSS SOUTHWEST ALASKA WILL BE RIGHT ON THE
HEELS OF THE SHORT-WAVE TROUGH MOVING THROUGH TODAY. A POTENTIAL
VORTICITY ANOMALY (ASSOCIATED WITH THE UPPER LOW) WILL MOVE ACROSS
THE WESTERN GULF TUESDAY BRINGING EVEN STRONGER WINDS THAN TODAY.
THESE WINDS WILL GRADUALLY DIMINISH WEDNESDAY INTO THURSDAY AS
THE LOW EXITS TO THE EAST AND COLD AIR ADVECTION COMES TO AN END.

SOUTHWEST ALASKA/EASTERN BERING...DEFORMATION ZONE WHICH IS
PRODUCING SNOW ALONG THE ALASKA AND ALEUTIAN RANGES WILL LOSE ITS
FORM BY LATE TONIGHT AS THE LOW OVER THE GULF PULLS NORTHEASTWARD.
THE REST OF SOUTHWEST ALASKA WILL REMAIN MOSTLY DRY. THE EXCEPTION
TO THIS WILL BE THE IMMEDIATE COASTAL AREAS AND NORTH SIDE OF THE
ALASKA PENINSULA WHERE COLD AIR MOVING OVER RELATIVELY WARM WATERS
OF THE EASTERN BERING WILL PRODUCE A STEADY STREAM OF SNOW SHOWERS.
STRONG GUSTY WINDS WILL ALSO PERSIST THROUGH THE DAY TUESDAY...
ESPECIALLY ALONG THE COAST AND THROUGH GAPS OF THE ALASKA PENINSULA.
COLD ADVECTION WILL THEN COME TO AN END AND THE SURFACE PRESSURE
GRADIENT WILL GRADUALLY WEAKEN AS GULF LOW EXITS TO THE EAST...
ALLOWING WINDS TO DIMINISH ACROSS THE REGION. COLD AND DRY AIR
WILL SETTLE IN MID TO LATE IN THE WEEK AS HIGH PRESSURE BUILDS IN
FROM THE WEST.

CENTRAL TO WESTERN BERING/ALEUTIANS...RIDGE OVER THE WESTERN BERING
WILL UNDERGO SOME UNDULATIONS AS ENERGY MOVES UP ITS WEST SIDE...
BUT WILL ULTIMATELY STRENGTHEN AND BUILD EASTWARD AS WE HEAD THROUGH
THE WEEK. THUS...EXPECT BENIGN CONDITIONS ACROSS THE REGION.

.LONG TERM FORECAST...A STRONG HIGH AMPLITUDE RIDGE WILL DOMINATE
ALASKA THROUGH THE DAY 4 THROUGH 7 TIME PERIOD PRODUCING DRY AND
SEASONABLY COOL CONDITIONS. THE RIDGE WILL GRADUALLY BUILD EASTWARD
TOWARD THE MAINLAND LATE IN THE WEEK...AT WHICH POINT PACIFIC STORMS
WILL BEGIN TO AFFECT THE WESTERN ALEUTIANS. MODEL SPREAD IS LARGE
AND RUN-TO-RUN CONSISTENCY IS POOR...MAKING FORECAST CONFIDENCE FOR
THE WESTERN ALEUTIANS VERY LOW.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE WARNING...130 132 150
FIRE WEATHER...NONE.

SEB OCT 12