Gale Warning 691, NWS Anchorage, AK

368 
FZAK61 PAFC 262311
OFFAER

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 PM AKDT WED OCT 26 2011

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.

PKZ399-271500-
400 PM AKDT WED OCT 26 2011
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A 991 MB LOW WILL CROSS THE ALASKA PENINSULA TONIGHT AND MOVE TO 56N
154W THU MORNING AND THEN TO 55N 146W AT 991 MB THU EVENING. THIS LOW
WILL MERGE WITH A LARGE LOW IN THE NORTHEASTERN PACIFIC FRI MORNING. 
$$

PKZ351-271500-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W
400 PM AKDT WED OCT 26 2011

.TONIGHT...SW WIND 25 KT. SEAS 19 FT. 
.THU...SE WIND 25 KT. SEAS 12 FT. RAIN SHOWERS. 
.THU NIGHT...SE WIND 20 KT. SEAS 11 FT. RAIN.
.FRI...S WIND 15 KT. SEAS 10 FT. 
.FRI NIGHT...SE WIND 35 KT. SEAS 10 FT. 
.SAT AND SUN...SW WIND 30 KT. SEAS 13 FT. 
.MON...S WIND 25 KT. SEAS 14 FT.  
$$

PKZ352-271500-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W
400 PM AKDT WED OCT 26 2011

.TONIGHT...SW WIND 30 KT BECOMING SE AFTER MIDNIGHT. SEAS 21 FT
SUBSIDING TO 14 FT AFTER MIDNIGHT. RAIN. 
.THU...S WIND 25 KT. SEAS 14 FT. RAIN.
.THU NIGHT...W WIND 20 KT. SEAS 13 FT. 
.FRI...SW WIND 25 KT. SEAS 10 FT. 
.FRI NIGHT...S WIND 30 KT. SEAS 10 FT. 
.SAT...SW WIND 35 KT. SEAS 16 FT. 
.SUN AND MON...SW WIND 30 KT. SEAS 15 FT.  

$$

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
138 PM AKDT TUE OCT 25 2011

.ANALYSIS AND UPPER LEVELS...

A POWERFUL 965 MB LOW RESIDES OVER THE BARREN ISLANDS REGION BETWEEN
KODIAK ISLAND AND THE KENAI PENINSULA AND HAS REACHED ITS PEAK
INTENSITY EARLY THIS AFTERNOON. AN ASSOCIATED STRONG WEATHER FRONT
EXTENDS FROM NEAR ANCHORAGE THROUGH PRINCE WILLIAM SOUND AND
SOUTHEAST THROUGH THE CENTRAL GULF OF ALASKA. MODERATE TO HEAVY
PRECIPITATION IS FALLING WITH THIS SYSTEM...ESPECIALLY ALONG PRINCE
WILLIAM SOUND AND ADJACENT MOUNTAINS...WITH SNOW AT HIGHER ELEVATIONS
INCLUDING COOPER LANDING...GLEN ALPS IN ANCHORAGE...AND THROUGH
THOMPSON PASS NORTHEAST OF VALDEZ.

A LARGE DEFORMATION ZONE EXISTS ON THE BACK SIDE OF THE LOW OVER
SOUTHWEST ALASKA AS THIS SYSTEM INTERACTS WITH A WEAKER LOW OVER THE
Y-K DELTA REGION THAT IS PUSHING NORTH. COLD AIR ALOFT IS CURRENTLY
POURING SOUTH CHANGING THE PRECIPITATION OVER TO SNOW AS FAR SOUTH AS
THE ALASKA PENINSULA.

ANOTHER WEAKER LOW PRESSURE SYSTEM IS PUSHING EAST ACROSS THE BERING
SEA AND WILL MOVE ACROSS THE AKPEN LATE TONIGHT AND WEDNESDAY MORNING
TO A POSITION SOUTH OF KODIAK LATE WEDNESDAY NIGHT.

.MODEL DISCUSSION...

MODELS ARE IN GOOD AGREEMENT OVER THE NEXT COUPLE OF DAYS IN TAKING
LOW PRESSURE EAST ACROSS THE NORTHERN GULF WHILE WEAKENING AND THEN
MAKING LANDFALL BETWEEN CORDOVA AND YAKUTAT BY MIDDAY WEDNESDAY. COLD
ADVECTION ON THE BACK SIDE WILL MAKE FOR A TRICKY RAIN/SNOW FORECAST
FROM THE MAT-SU VALLEY SOUTH TO ANCHORAGE FOR THE WEDNESDAY MORNING
COMMUTE.

.SHORT TERM FORECAST...

SOUTHCENTAL...

STRONG WEATHER FRONT WILL CONTINUE TO PUSH INLAND ACROSS THE PRINCE
WILLIAM SOUND REGION AND WEAKEN THROUGH THIS EVENING. MODERATE TO
HEAVY RAINFALL WILL CONTINUE TO FALL WITH RISING FREEZING LEVELS OVER
THE HIGHER ELEVATIONS...RESULTING IN MINOR FLOODING THROUGHOUT THE
ZONE. THOMPSON PASS SHOULD SEE A CHANGEOVER TO RAIN AS A RESULT OF
THESE RISING FREEZING LEVELS...AND THE MELTING OF THE SNOWFALL AT
HIGHER ELEVATIONS SHOULD ALSO CONTRIBUTE TO THE RISE OF RIVERS AND
SMALL STREAMS. AN ADDITIONAL 2 TO 8 INCHES OF RAINFALL IS EXPECTED
THROUGH EARLY WEDNESDAY MORNING.

ANOTHER BIG CONCERN IN THE SHORT TERM IS THE STRONG WINDS ON THE BACK
SIDE OF THE LOW. HIGH WIND WARNING HAS BEEN ISSUED FOR KODIAK...AND
WITH SUCH STRONG COLD ADVECTION AND THE IMPRESSIVE DYNAMICS INDICATED
BY SATELLITE PRESENTATION AND MODEL FORECASTS...DAMAGING WEST WINDS
OF 40 TO 60 MPH WITH GUSTS TO 75 MPH ARE EXPECTED TO SPREAD NORTH
ACROSS THE ISLAND THROUGH THIS EVENING.

FOR ANCHORAGE...TEMPERATURES WILL COOL OVERNIGHT BUT WILL GENERALLY
REMAIN ABOVE FREEZING AS TEMPERATURES ALOFT COOL MORE RAPIDLY. THE
CURRENT THINKING IS THAT PRECIPITATION SHOULD CHANGE FROM RAIN TO
SNOW DURING THE EARLY MORNING HOURS...THEN END BY LATE MORNING AS A
SHORTWAVE DISTURBANCE MOVES PAST THE AREA. THE EXPECTATION IS THAT A
TRACE TO PERHAPS ONE INCH OF WET SLUSHY SNOW...STICKING MAINLY ON
GRASS AND OTHER ELEVATED SURFACES...WILL FALL NEAR SEA LEVEL WITH
PERHAPS ONE TO THREE INCHES AT THE HIGHER ELEVATIONS. SEE SPECIAL
WEATHER STATEMENT FOR MORE DETAILS ON SNOW POTENTIAL FOR ANCHORAGE.

PRECIPITATION SHOULD END FROM SOUTHWEST TO NORTHEAST FROM LATE
MORNING THROUGH MIDDAY WEDNESDAY...WITH PARTIAL CLEARING TAKE PLACE
BEFORE CLOUDS ASSOCIATED WITH THE NEXT SYSTEM APPROACH THE REGION
WEDNESDAY NIGHT.

SOUTHWEST ALASKA...

IMPRESSIVE DEFORMATION ZONE EXISTS OVER THE KUSKOKWIM VALLEY AND
BRISTOL BAY ZONE...BUT WILL SLOWLY DISSIPATE AS THE LOWS INTERACTING
WITH ONE ANOTHER MOVE FURTHER APART THROUGH TONIGHT. COLD AIR
SPILLING INTO THE REGION FROM THE NORTH AND WEST IS HELPING TO CHANGE
THE PRECIPITATION OVER TO SNOW AS FAR SOUTH AND EAST AS KING SALMON.

PRECIPITATION SHOULD BECOME ISOLATED TO SCATTERED BY TONIGHT MOST
AREAS BEFORE THE NEXT SYSTEM BRUSHES THE REGION FROM WEST THROUGH
SOUTH WEDNESDAY NIGHT. BEST CHANCES FOR MIXED PRECIPITATION SHOULD BE
FROM THE WESTERN CAPES EAST THROUGH THE BRISTOL BAY ZONE.

BERING SEA/ALEUTIANS...

A RELATIVELY WEAKER WEATHER SYSTEM WILL CONTINUE TO BRING GALE FORCE
WINDS...AS WELL AS RAIN OUT AHEAD OF ITS ASSOCIATED WEATHER FRONT
WITH SCATTERED SNOW SHOWERS ON THE BACK SIDE. IT WILL MOVE OVER THE
PRIBILOFS WEDNESDAY MORNING AND THEN MOVE TO NEAR KODIAK ISLAND LATE
WEDNESDAY NIGHT.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...HIGH WIND WARNING...171
MARINE...GALES...125 129 138 140 141 150 155 160 165 170 171 172 175
                 176 179
         STORMS...120 130 132
FIRE WEATHER...NONE.

29 OCT 11