Gale Warning 585, NWS Anchorage, AK

000 
FZAK61 PAFC 211143
OFFAER

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 AM AKDT MON SEP 21 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.

PKZ399-220200-
400 AM AKDT MON SEP 21 2009
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A 987 MB LOW NEAR 59N 147W WILL MOVE ON SHORE 60N 144W AT 996 MB MON
AFTERNOON. WEAK HIGH PRESSURE WILL BUILD INTO THE GULF THROUGH TUE
NIGHT.
$$

PKZ351-220200-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W
400 AM AKDT MON SEP 21 2009

...GALE WARNING TODAY...

.TODAY...SW WIND 35 KT DIMINISHING TO 25 KT. SEAS 21 FT. 
.TONIGHT...SW WIND 20 KT. SEAS 12 FT. 
.TUE...W WIND 15 KT. SEAS 8 FT. 
.TUE NIGHT...NW WIND 20 KT. SEAS 8 FT. 
.WED...NW WIND 25 KT. SEAS 7 FT. 
.THU...SE WIND 35 KT. SEAS 16 FT. 
.FRI...S WIND 20 KT. SEAS 18 FT.  

$$

PKZ352-220200-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W
400 AM AKDT MON SEP 21 2009

.TODAY...SW WIND 25 KT. SEAS 19 FT. 
.TONIGHT...W WIND 25 KT. SEAS 11 FT. 
.TUE...W WIND 15 KT. SEAS 8 FT. 
.TUE NIGHT...N WIND 15 KT. SEAS 6 FT. 
.WED...N WIND 25 KT. SEAS 7 FT. 
.THU...S WIND 35 KT. SEAS 16 FT. 
.FRI...SW WIND 30 KT. SEAS 23 FT.  

$$

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AKDT SUN SEP 20 2009

.ANALYSIS AND UPPER LEVELS...LONG-WAVE TROUGH REMAINS CENTERED
OVER THE ALASKA REGION WITH A BLOCKING RIDGE JUST UPSTREAM OVER
EASTERN SIBERIA. AN ANCHOR LOW IS LOCATED OVER THE WESTERN ALASKA
PENINSULA ALTHOUGH A STRONG SHORTWAVE IS UNDERCUTTING THE LOW AND
WILL BECOME THE NEW DOMINANT FEATURE IN THE GULF OF ALASKA THROUGH
THE REMAINDER OF THE WEEKEND. ANOTHER WEAKER SHORTWAVE ROTATING
AROUND THE NORTHWESTERN SIDE OF THE UPPER LOW IS BRINGING RAIN TO THE
ALASKA PENINSULA AND EASTERN ALEUTIANS TODAY. WAY OUT WEST IS THE
REMNANTS OF THE TYPHOON CHOI-WAN...NOW LOCATED SOUTHEAST OF THE
KAMCHATKA PENINSULA. DEEP TROPICAL MOISTURE IS EVIDENT ON WATER VAPOR
IMAGERY SPREADING NORTH AND EAST IN ADVANCE OF THE SYSTEM.

.MODEL DISCUSSION...MODELS CONTINUE TO HAVE AN EXCELLENT HANDLE ON
THE SHORT TERM AND CONTINUE TO FALL BEYOND 84 HOURS. IN THE SHORT
TERM ONLY MINOR DIFFERENCES EXIST BETWEEN THE SPEED AND INTENSITY OF
THE LOW THAT WILL MOVE INTO GULF TODAY. THE CURRENT [00Z] GFS AND
ECMWF AND UKMET ARE ALL IN LINE WITH EACH OTHER BUT THE 00Z NAM IS
RUNNING ABOUT 3 HOURS BEHIND THE OTHER MODELS AND THE 00Z CANADIAN IS
JUST A BIT FURTHER EAST. THE GROUPED MODELS BRING THE LOW ONSHORE
NEAR SEWARD EARLY MONDAY MORNING WHILE THE NAM FALLS EVEN
SLOWER...BRINGING IT THROUGH WESTERN PRINCE WILLIAM SOUND IN THE
AFTERNOON. THE 06Z RUN OF THE NAM HAS NOW COME INTO LINE WITH THE
OTHER MAJOR MODELS AND CONFIDENCE IN THE SHORT TERM REMAINS HIGH.
BEYOND MONDAY...THE BIGGEST CHALLENGE WITH THE FORECAST WILL CONTINUE
TO BE THE REMNANTS OF TYPHOON CHOI-WAN. MODELS THIS MORNING ARE NOW
BACKING AWAY FROM SENDING THE STORM SOUTH OF THE ALEUTIAN CHAIN AND
INTO THE GULF. THE NEW SOLUTION BRINGS THE STORM INTO THE EASTERN
BERING BEFORE DRIFTING EAST AND INTO THE GULF. AS HAS BEEN THE CASE
FOR THE LAST FEW DAYS...CONFIDENCE IN THE STORM TRACK REMAINS LOW AND
WILL NEED TO CONTINUE TO BE WATCHED.

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...BANDS OF SHOWERS ASSOCIATED WITH A FRONT
SWEEPING THROUGH THE GULF ARE APPERANT ON RADAR THIS MORNING. LOW AND
MID LEVEL CLOUDS WILL BEGIN TO SPREAD INLAND. MAXIMUM GALE FORCE
WINDS WITH POTENTIAL STORM FORCE GUSTS ASSOCIATED WITH THE FRONT WILL
CONTINUE ALONG THE GULF COAST TODAY THROUGH THIS EVENING. THE 30 MPH
GUSTS THAT WESTERN ANCHORAGE SAW OVERNIGHT SHOULD SLOWLY DIMINISH
THIS MORNING...WHILE THOSE WINDS CAN STILL BE EXPECTED ALONG THE
HILLSIDE AND DOWN THROUGH THE PORTAGE VALLEY. AS WAS PREVIOUSLY
MENTIONED...THE FORECAST BEGINS TO GET A LITTLE TRICKY FOR TOMORROW
NIGHT AND INTO TUESDAY MORNING. IT IS STILL LOOKING LIKE THE FIRST
SIGNS OF TERMINATION DUST AND SNOW FOR THE SEASON WILL BE FALLING.
TEMPERATURES AT THE SURFACE WILL STILL BE TOO WARM FOR ANY
ACCUMULATION BUT SNOW COULD STILL BE EXPECTED ALL OF THE WAY DOWN TO
SEA LEVEL TUESDAY MORNING.

SOUTHWEST ALASKA...COLD AIR WILL BEGIN TRANSITIONING SOUTH ACROSS THE
REGION LATE TONIGHT ASSOCIATED WITH A CHUKCHI SEA LOW. OVERNIGHT
TEMPERATURES ARE EXPECTED TO DIP BELOW FREEZING FOR AREAS IN THE
LOWER KUSKOKWIM VALLEY MONDAY NIGHT...MEANWHILE AREAS IN THE
KUSKOKWIM DELTA AND BRISTOL BAY WILL ONLY FLIRT WITH THE FREEZING
VALUES. COLD AIR ADVECTION SNOW SHOWERS AND BREEZY NORTHWEST FLOW
WILL PREVAIL THROUGH TUESDAY WHEN TRANSIENT HIGH PRESSURE BUILDS OVER
THE REGION AHEAD OF THE WARM ADVECTION ASSOCIATED WITH THE TROPICAL
REMNANTS.

BERING SEA/ALEUTIANS...BROAD NORTHERLY FLOW AND RELATIVELY TRANQUIL
WEATHER WILL PREVAIL BEFORE STORM FORCE WINDS MOVE ACROSS THE WESTERN
ALEUTIANS MONDAY ASSOCIATED WITH THE TROPICAL REMNANTS. MANY
QUESTIONS STILL REMAIN SURROUNDING THE MID WEEK FORECAST BUT CERTAIN
A STRONG FALL STORM WILL IMPACT THE MAJORITY OF THE BERING SEA DURING
THAT TIME FRAME.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE WARNING...120 125 130 132 138 140 150 175
         STORM WARNING 176.
FIRE WEATHER...NONE.

SHEA SEP 09