Gale Warning 359, NWS Anchorage, AK

000 
FZAK61 PAFC 162320
OFFAER

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 PM AKDT THU APR 16 2009

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.

PKZ399-171400-
400 PM AKDT THU APR 16 2009
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A 995 MB LOW NEAR 56N 147W WILL MOVE SOUTHWEST TO 53N 150W AND WEAKEN
TO 1000 MB FRI AFTERNOON. THE LOW WILL WEAKEN FURTHER TO 1005 MB SAT
AFTERNOON NEAR 53N 147W.
$$

PKZ351-171400-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W
400 PM AKDT THU APR 16 2009

.TONIGHT...E WIND 30 KT...DIMINISHING TO 20 KT AFTER MIDNIGHT. SEAS
12 FT. 
.FRI...E WIND 20 KT BECOMING NE 10 KT DURING THE AFTERNOON. SEAS
9 FT. 
.FRI NIGHT...NE WIND 15 KT. SEAS 7 FT. RAIN AND SNOW.
.SAT...VARIABLE WIND 10 KT. SEAS 5 FT. 
.SAT NIGHT...E WIND 15 KT. SEAS 5 FT. 
.SUN...NE WIND 15 KT. SEAS 5 FT. 
.MON...NW WIND 20 KT. SEAS 7 FT. 
.TUE...W WIND 15 KT. SEAS 5 FT.  

$$

PKZ352-171400-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W
400 PM AKDT THU APR 16 2009

.TONIGHT...VARIABLE WIND 20 KT BECOMING E AFTER MIDNIGHT...EXCEPT N
WIND 25 KT WEST OF 148W. SEAS 11 FT. RAIN AND SNOW. 
.FRI...E WIND 25 KT. SEAS 10 FT. RAIN AND SNOW. 
.FRI NIGHT...E WIND 20 KT BECOMING VARIABLE 15 KT AFTER MIDNIGHT.
SEAS 7 FT. RAIN AND SNOW. 
.SAT AND SAT NIGHT...VARIABLE WIND 10 KT. SEAS 5 FT. 
.SUN...NW WIND 15 KT. SEAS 5 FT. 
.MON...NW WIND 20 KT. SEAS 7 FT. 
.TUE...W WIND 15 KT. SEAS 5 FT.  

$$

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
400 AM AKDT THU APR 16 2009

.ANALYSIS AND UPPER LEVELS...
THE LOW COMPLEX REMAINS OVER THE GULF OF ALASKA...WITH VARIOUS LOWS
WITHIN THE LARGE SCALE CIRCULATION. ELSEWHERE AT THE SURFACE...HIGH
PRESSURE IS LOCATED OVER THE BERING SEA AND WESTERN AND CENTRAL
ALEUTIANS. THE PRESSURE GRADIENT BETWEEN THESE TWO SYSTEMS IS
RESULTING IN GUSTY NORTHERLY FLOW ACROSS THE EASTERN ALEUTIANS AND
SOUTHWEST ALASKA...ALTHOUGH WINDS ARE LESSENING AS THE GRADIENT
RELAXES.

IN THE UPPER LEVELS...A LARGE CUT-OFF LOW IS CENTERED NEAR 50N 150W.
VARIOUS UPPER WAVES ARE ROTATING WITHIN THIS CIRCULATION. THE CUT-OFF
LOW IS AT THE BASE OF A HIGHLY AMPLIFIED TROUGH CENTERED OVER THE
ALASKA MAINLAND...AND EXTENDING INTO THE GULF OF ALASKA. RIDGING IS
LOCATED OVER THE WESTERN AND CENTRAL ALEUTIANS AND BERING SEA.

.MODEL DISCUSSION...
MODELS ARE IN GOOD AGREEMENT IN HANDLING THE PATTERN THROUGH
SATURDAY. DIFFERENCES ARISE IN THE POSITIONING AND STRENGTH OF
INDIVIDUAL LOWS EMBEDDED WITHIN THE LOW COMPLEX. THE NAM/GFS
SOLUTIONS WERE USED TO CONSTRUCT THE MORNING FORECAST PACKAGE...WITH
MAIN FOCUS ON THE FIRST 60 HOURS.

.SHORT TERM FORECAST...
.SOUTHCENTRAL...FOCUS THROUGH THE END OF THE WEEK CONTINUES TO BE THE
IMPACT OF INDIVIDUAL LOWS AND WAVES ROTATING WITHIN THE COMPLEX.
PRECIPITATION WILL BE MAINLY CONFINED TO COASTAL LOCATIONS...ALTHOUGH
MOISTURE WILL PERIODICALLY SURGE INLAND AS INDIVIDUAL LOWS AND
SURFACE WAVES ROTATE AROUND THE TOP OF THE COMPLEX. IN
GENERAL...EXPECT INLAND LOCATIONS TO REMAIN DRY...ALTHOUGH THE COPPER
RIVER BASIN WILL SEE INCREASED SHOWERS DUE TO SOUTHEASTERLY FLOW
ALOFT.

.SOUTHWEST...GUSTY NORTHERLY FLOW WILL BE THE MAIN STORY ACROSS THE
AREA THROUGH FRIDAY...AS THE GRADIENT ON THE BACKSIDE OF THE LOW
COMPLEX REMAINS TIGHT. THE AKPEN WILL SEE SCATTERED SNOW SHOWERS AND
BLOWING SNOW TODAY IN RESPONSE TO THIS COLD ADVECTION. ELSEWHERE
ACROSS SOUTHWEST...EXPECT RELATIVELY TRANQUIL WEATHER TO PERSIST AS
WE HEAD INTO THE WEEKEND.

.BERING SEA AND ALEUTIANS...CONDITIONS WILL REMAIN FAIRLY QUIET
ACROSS THE ALEUTIANS AND PRIBILOFS OVER THE NEXT SEVERAL DAYS AS HIGH
PRESSURE REMAINS OVER THE REGION. GUSTY NORTHERLY WINDS WILL CONTINUE
OVER THE EASTERN ISLANDS TODAY...BUT WILL BE DISSIPATING AS THE
GRADIENT RELAXES. SCATTERED SHOWERS ASSOCIATED WITH A WEATHER FRONT
WILL BEGIN IMPACTING THE WESTERN ALEUTIANS THURSDAY NIGHT INTO
FRIDAY...BUT WILL NOT MAKE MUCH PROGRESSION EASTWARD AS THE UPPER
RIDGE REMAINS IN CONTROL.

.LONG TERM FORECAST...
HIGHLY AMPLIFIED PATTERN WILL STAY IN PLACE AS WE HEAD INTO THE
WEEKEND. MODELS CONTINUE TO HINT AT THE PATTERN BREAKING DOWN BY
EARLY NEXT WEEK...BUT DETAILS THIS FAR OUT ARE STILL CLOUDY. THROUGH
THE WEEKEND ANTICIPATE HIGH PRESSURE OVER THE BERING SEA AND
ALEUTIANS WITH THE LOW COMPLEX REMAINING OVER THE SOUTHERN GULF.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...GALE...120 130 132
         HEAVY FREEZING SPRAY...179
FIRE WEATHER...NONE

NRH APR 09