Gale Warning 792, NWS Anchorage, AK

860 
FZAK61 PAFC 251228
OFFAER

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 AM AKST THU DEC 25 2008

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.

PKZ399-260300-
400 AM AKST THU DEC 25 2008
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A 987 MB LOW WILL MOVE TO 58N 152W THURSDAY AFTERNOON AND THEN MOVE
TO 59N 143W FRIDAY AFTERNOON INTENSIFYING TO 971 MB. THIS LOW WILL
THEN REMAIN NEARLY STATIONARY THROUGH FRI NIGHT WITH LITTLE CHANGE 
IN PRESSURE. 

$$

PKZ351-260300-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W
400 AM AKST THU DEC 25 2008

...STORM WARNING TONIGHT AND FRIDAY...

.TODAY...SW WIND 15 KT INCREASING TO S TO SE 20 TO 30 KT IN THE
AFTERNOON. SEAS 8 FT. RAIN AND SNOW. 
.TONIGHT...SW WIND 30 KT INCREASING TO W 40 TO 50 KT AFTER MIDNIGHT. 
SEAS BUILDING TO 16 FT. RAIN.
.FRI...W WIND 45 TO 55 KT. SEAS 23 FT. SNOW AND RAIN SHOWERS. 
.FRI NIGHT...W WIND 35 TO 45 KT. SEAS 25 FT. 
.SAT...NW WIND 30 TO 40 KT. SEAS 20 FT. 
.SUN...NE WIND 30 KT. SEAS 12 FT. 
.MON...E WIND 25 KT. SEAS 9 FT.  

$$

PKZ352-260300-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF 144W
400 AM AKST THU DEC 25 2008

...STORM WARNING FRIDAY...

.TODAY...S TO SW WIND 30 KT. SEAS 6 FT BUILDING TO 12 FT. 
RAIN AND SNOW. 
.TONIGHT...W TO NW WIND 35 TO 45 KT. SEAS 16 FT. RAIN.
.FRI...W TO NW WIND 45 TO 55 KT. SEAS 24 FT. 
.FRI NIGHT...W WIND 40 TO 50 KT. SEAS 28 FT. 
.SAT...NW WIND 35 TO 45 KT. SEAS 25 FT. 
.SUN...NW WIND 25 TO 35 KT. SEAS 15 FT. 
.MON...NE WIND 20 KT. SEAS 10 FT.  

$$

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
230 PM AKST WED DEC 24 2008

.MODEL DISCUSSION...
MODELS IN REMARKABLY GOOD AGREEMENT TODAY GIVING SOME CONFIDENCE TO
THE FORECAST. THIS IS OFFSET BY THE POOR RUN TO RUN CONSISTENCY AND
POOR RECENT PERFORMANCE.

.ANALYSIS AND UPPER LEVELS...
MEAN UPPER RIDGE NEGATIVELY TILTED ALONG ABOUT 155 DEGREES WEST
LONGITUDE. STRONG AND PROGRESSIVE JET ON THE COLD SIDE (EASTERN) OF
THE HIGH FROM KODIAK SOUTHEASTWARD TO SAN FRANCISCO. INTERESTING
DYNAMICS ON THE WARM SIDE OF THE RIDGE WITH A LOW OVER THE CENTRAL
BERING SEA AND A LOW MOVING UP FROM THE SOUTH JUST EAST OF THE DATE
LINE. BOTH LOWS ARE JUICY...ESPECIALLY THE LATTER ONE.

.SHORT TERM FORECAST...
THE TWO LOWS WILL MERGE INTO AN ELONGATED FRONT SOMEWHAT TONIGHT...
BUT MOST OF THE MOISTURE FROM THE SOUTHERN LOW WILL STAY SOUTH OF 53
DEGREES NORTH LATITUDE. THE BERING LOW AND ITS LONG FRONT WILL MOVE
EAST AS THE UPPER RIDGE RETREATS SOUTHWARD...ON THE FIRST PART OF
ITS RETROGRADING JOURNEY.

PRECIPITATION FROM THE LOW SYSTEM WILL REACH THE WEST COAST OF
ALASKA BY EVENING AND SPREAD ACROSS SOUTHWEST ALASKA TONIGHT. AS
THE SURFACE LOW MOVES INTO KUSKOKWIM BAY EARLY THURSDAY MORNING
BLIZZARD CONDITIONS WILL DEVELOP OVER THE KUSKOKWIM DELTA AND
CONTINUE THROUGH EARLY AFTERNOON.

BY THURSDAY AFTERNOON THE FORMER BERING LOW WILL BE NEAR MCGRATH...
WITH A SECONDARY LOW ASSOCIATED WITH THE SOUTHERN SYSTEM DEVELOPING
JUST NORTHEAST OF KODIAK ISLAND. SIGNIFICANT SNOWFALL IS EXPECTED
OVER MOST OF SOUTHERN ALASKA THURSDAY AND THURSDAY NIGHT.

BY FRIDAY THE NORTHERN LOW WILL BE DISSIPATING OVER CENTRAL ALASKA
AND THE SOUTHERN SYSTEM WILL BECOME THE DOMINANT LOW. THE SURFACE
LOW WILL SPIN UP ALONG THE NORTH GULF COAST THROUGH FRIDAY AFTERNOON
WITH SNOW CONTINUING OVER SOUTH CENTRAL ALASKA. LOTS OF COLD
ADVECTION WITH NORTHWEST FLOW AT ALL LEVELS WEST OF THE LOW.

.LONG TERM FORECAST...
THE FEATURE OF NOTE FOR SATURDAY THROUGH THE REMAINDER OF THE
FORECAST (NEXT WEDNESDAY) AND BEYOND WILL BE THE BLOCKING RIDGE THAT
DEVELOPS OVER THE BERING SEA. THIS WILL ANCHOR THE UPPER LOW ALONG
ABOUT 140 DEGREES WEST LONGITUDE. SIBERIAN AIR WILL ROTATE AROUND
THE BLOCK AND ACROSS ALASKA USHERING IN A COLD EPISODE. EXACTLY HOW
COLD IT WILL GET AND OTHER DETAILS ARE SKETCHY AS THE ONLY FEATURE
WITH ANY FORECAST CONFIDENCE IS THE BLOCKING RIDGE ITSELF...ALL
DOWNSTREAM ACTIVITY WITH THE UPPER LOW IS SUBJECT TO NUMEROUS
NUANCES. BUT COLD TO VERY COLD IS LIKELY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WARNING 155.
MARINE...STORM WARNING 130.
         GALE WARNING 120 121 132 138 150 155 160 165 179 180 185.
         HEAVY FREEZING SPRAY WARNING 129 160 180 185.
FIRE WEATHER...NONE.

LUDWIG DEC 08