Gale Warning 462, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
407 PM AKST SUN DEC 11 2011

.SHORT TERM...EARLY AFTERNOON WATER VAPOR SATELLITE LOOP REVEALS
AN AMPLIFIED UPPER LEVEL RIDGE OVER THE ALASKAN
PANHANDLE...SLOWLY DRIFTING EASTWARD AND AN UPPER LEVEL SHORTWAVE
TROUGH INTENSIFIES ACROSS THE WESTERN GULF. INFRARED SATELLITE
LOOP SHOWS A 972 MB LOW JUST SOUTHWEST OF KODIAK ISLAND WITH A
WARM FRONT STRETCHING EAST-SOUTHEASTWARD ACROSS THE CENTRAL GULF.
A TRIPLE POINT FORMS JUST SOUTH OF KODIAK WITH ITS COLD FRONT
STRETCHING SOUTHWARD. AN AREA OF WEAKENING SUBSIDENCE UNDER A
RIDGE OF HIGH PRESSURE MOVES EAST INTO CANADA. A SLOW WARMING
TREND IS ON THE WHEEL ALONG THE FRONTAL BOUNDARY AND TEMPERATURES
ACROSS THE PANHANDLE WARM UP TO THE MID TO UPPER 30S...EXCEPT
HAINES AREA WHERE COLDER AIR RESIDING IN THE MID 20S. AS THE
RIDGE MOVES EAST...SOUTHERLY PRESSURE GRADIENT GENERATED SOUTH
WIND 25 TO 30 MPH OVER SKAGWAY AND SMALL CRAFT WIND ACROSS
NORTHERN LYNN CANAL.

MODELS ARE IN FAIR AGREEMENT WITH THE 972 MB LOW SOUTHWEST OF
KODIAK WEAKENS A BIT TO 977 MB THIS AFTERNOON AND CONTINUES
DRIFTING NORTHEAST INTO THE NORTHERN GULF AND DEEPEN TO ABOUT 968
MB BY TONIGHT. THE WARM FRONT ENTERING THE EASTERN GULF WILL MOVE
ONSHORE OVER SOUTHEAST ALASKA THROUGH MONDAY WHILE WEAKENING.
REFRESHED THE INHERITED FORECAST PACKAGE WITH THE NAM FOR TONIGHT
AND MONDAY IT IT WAS INITIALIZED BEST. THE WATER VAPOR SATELLITE
IMAGERY ALSO SHOWS A DRY SLOT AROUND THE LOW CENTER...PUSHING A
DEFORMATION ZONE NORTHEASTWARD INTO PRINCE WILLIAM SOUND. WITH THE
INCOMING WARM FRONT...EXPECT TEMPERATURES WILL SLOWLY RISE THROUGH
THE EVENING AND OVERNIGHT. DUE TO THE RESIDING COLD AIR OVER
HAINES...OVERRUNNING WILL LIKELY TO OCCUR AND EXPECT 4 TO 8 INCHES
OF SNOW ACCUMULATION FOR HAINES AND HIGHWAYS TO THE BORDER. THE
WARMING TREND WILL CONTINUE TO AFFECT THE NORTHERN MOST ZONES
THROUGH LATE TONIGHT...THEN SNOW WILL LIKELY TO CHANGING OVER RAIN
TOWARDS THE EARLY MORNING HOURS.

HAVE CANCELLED THE INHERITED WINTER WEATHER ADVISORIES FOR
NORTHERN AND CENTRAL PANHANDLE...BUT KEPT THE WINTER STORM WARNING
FOR HAINES THROUGH 3 AM TONIGHT. THE INCOMING FRONT WILL GENERATE
STORM FORCE WINDS ACROSS THE OUTER WATERS THROUGH TONIGHT THEN
SUBSIDING TO GALE FORCE BY LATE TONIGHT INTO MONDAY...INCLUDING
CROSS SOUND...SOUTHERN CHATHAM AND SUMNER. PAVED ALL OTHER INNER
CHANNELS WITH SMALL CRAFT WINDS. THE FRONT WILL ALSO BRING STRONG
GUSTY WINDS OVER THE PANHANDLE COASTAL SECTIONS FROM YAKUTAT
SOUTHEAST TO KLAWOCK THIS EVENING AND TONIGHT. THE SOUTHERLY
PRESSURE GRADIENT WILL CONTINUE TO WEAKEN AS THE RIDGE MOVES EAST
AWAY FROM THE AREA...AND THE FRONTAL BOUNDARY WILL MAINTAIN
INCREASING SOUTHEAST LOW TO MID LEVEL FLOW ACROSS THE FORECAST
AREA FOR SLOW WARMING THROUGH MONDAY. PRECIPITATION FROM THE
WEAKENING FRONT WILL MOST LIKELY RAIN ON MONDAY.

&&

.LONG TERM...RESIDUAL FRONT FINISHES MOVING THROUGH SOUTHEAST
ALASKA WITH A RIDGE BUILDING FOR TUESDAY. ANOTHER WEAKENING FRONT
WILL SHEER APART AS IT MOVES TO THE PANHANDLE COAST WEDNESDAY
NIGHT...AND THIS MAY BRING A BIT MORE PRECIPITATION FOR THURSDAY.
A STRONG LOW IS EXPECTED TO THE MOVE THE EASTERN ALEUTIANS AND
THEN TO THE BERING SEA AND ITS FRONT SHOULD BE MOVING THROUGH THE
PANHANDLE LATE THURSDAY AND FRIDAY OF THE WEEK.

GENERAL PATTERN IS LOOKING TO STAY FAIRLY SIMILAR WITH A LARGE
BROAD UPPER LEVEL LOW OVER THE BERING AND BROAD ALTHOUGH AT TIMES
WEAK UPPER LEVEL HIGH OVER THE EASTERN PACIFIC PERSISTING. THE
UPPER LEVEL FLOW PATTERN REMAINS PREDOMINATELY ZONAL WITHOUT A
SIGNIFICANT BLOCKING FEATURE OVER THE OVER THE WESTERN US.

FEW IS ANY CHANGES WERE DONE IN THE LATER PORTIONS OF THE
FORECAST. FORECAST CONFIDENCE IS AVERAGE.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND FROM 9 PM AKST THIS EVENING THROUGH LATE TONIGHT FOR
     AKZ027.
         STRONG WIND FROM 6 PM THIS EVENING TO MIDNIGHT AKST TONIGHT FOR
     AKZ022-023.
         WINTER STORM WARNING FROM 6 PM THIS EVENING TO 3 AM AKST MONDAY
     FOR AKZ019.
         STRONG WIND THROUGH MONDAY MORNING FOR AKZ017.
MARINE...STORM WARNING FOR PKZ051-052.
         GALE WARNING FOR PKZ022-033-035-041>043.
         SMALL CRAFT ADVISORY FOR PKZ011>013-021-031-032-034-036-053.

&&

AHN/BEZENEK