Gale Warning 285, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
1245 PM AKDT FRI OCT 24 2008

.SHORT TERM...A SHARP COLD FRONT IS SEEN ON SATELLITE THIS
MORNING ADVECTING EASTWARD ACROSS THE GULF. THE CAA CONTINUES
FROM 300 MB DOWN TO THE SURFACE FROM THE CENTRAL PANHANDLE
NORTHWARD WITH SNOW SHOWERS NOW REPORTED AT PAYA AND A MIX OF
RAIN, SNOW, AND ICE PELLETS FROM ICY STRAIT AND JUNEAU NORTHWARD.
THE CAA WILL CONTINUE THROUGH THE AFTERNOON WITH -10 TO -14 C
850 MB TEMPERATURES ADVECTING ACROSS THE PANHANDLE. WITH A MID
LEVEL TROUGH AND PVA AHEAD OF THE COLD FRONT SHOWERS WILL
CONTINUE THROUGH THE AFTERNOON ACROSS THE CENTRAL AND NORTHERN
PANHANDLE. ACROSS THE SOUTHERN PANHANDLE EXPECTING MOSTLY CLOUDY
SKIES TO CONTINUE WITH SHOWER ACTIVITY BEING ISOLATED AS THE PVA
IS MUCH LESS AT LOW AND MID LEVELS THERE. WITH A STRONG WESTERLY
SURFACE PRESSURE GRADIENT LOCATED ACROSS THE EASTERN GULF
TODAY...WINDS REMAIN GALE FORCE AND SEAS HAVE BUILT TO 25 FEET.
WIND ADVY GUSTS CONTINUE FOR THE NORTHERN OUTER COASTAL WATERS
AND NEAR SKAGWAY.

 FOR TONIGHT THE LOCALLY WINDY CONDITIONS WILL CONTINUE ALONG THE
OUTER COAST WITH THE STRONG WESTERLY SURFACE PRESSURE GRADIENT
AND WILL CONTINUE THE WIND ADVY THERE. EXPECT THE STRONG WINDS TO
CONTINUE IN SKAGWAY TONIGHT WITH THE SURFACE PRESSURE GRADIENT
ORIENTATION REMAINING FAVORABLE FOR STRONG WINDS...HOWEVER WINDS
NEAR HAINES WILL DIMINISH BY THE EARLY EVENING AS THE SURFACE
PRESSURE GRADIENT ORIENTATION WILL BECOME LESS FAVORABLE FOR
THEM. GALES WILL SLOWLY DIMINISH OVERNIGHT ALONG THE OUTER COAST
AS THE WESTERLY SURFACE PRESSURE GRADIENT BEGINS TO RELAX.
SHOWERS WILL CONTINUE THROUGH THE EVENING AS THE MID LEVEL TROUGH
NOW IN THE NORTHERN GULF ADVECTS EASTWARD...BUT SHOWERS WILL
SLOWLY DIMINISH FROM NORTHWEST TO SOUTHEAST AFTER THE MID LEVEL
TROUGH PASSES EASTWARD BY LATE TONIGHT. WITH THE COLD
TEMPERATURES ALOFT AND THE CAA CONTINUING THROUGH THE NIGHT AT
THE SURFACE EXPECTING THE MAJORITY OF THE SHOWERS FROM FREDERICK
SOUND NORTHWARD TO BE SNOW WITH UP TO 1 INCH OF SNOW
ACCUMULATION. WHILE SOUTH OF FREDERICK SOUND SNOW WILL MIX WITH
RAIN BY THE LATE EVENING WITH LITTLE TO NO SNOW ACCUMULATION AS
GROUND TEMPERATURES THERE REMAIN IN THE MIDDLE 40S.

 FOR TOMORROW A MID LEVEL RIDGE WILL ADVECT OVER THE PANHANDLE
AHEAD OF A DEVELOPING GALE FORCE LOW IN THE NORTHERN PACIFIC AND
THIS MID LEVEL RIDGE WILL SUPPRESS MUCH OF THE SHOWER ACTIVITY
ACROSS THE NORTHERN AND CENTRAL PANHANDLE BY EARLY SATURDAY
MORNING. THIS WILL GIVE WAY TO MOSTLY TO PARTLY CLOUDY SKIES
SATURDAY ACROSS THE PANHANDLE. WINDS WILL CONTINUE DIMINISH
BECOMING LIGHT ACROSS THE MAJORITY OF THE PANHANDLE BY LATE
MORNING TOMORROW AS THE SURFACE PRESSURE GRADIENT WEAKENS AND
BECOMES EASTERLY.

.LONG TERM...AFTER THE INITIAL COLD UPPER LOW IN THE ALASKAN
INTERIOR MOVES EASTWARD THE MODELS TREND TOWARD THE SLOW
PROGRESSION OF A LONGWAVE TROUGH ACROSS THE GULF OF ALASKA THROUGH
NEXT WEEK. THERE IS ALSO THE SUGGESTION OF STRONGER DEVELOPMENT
IN THE SOUTHERN PORTION OF THE TROUGH THAT COULD LEAD TO A CUTOFF
UPPER LOW FOR A SHORT TIME...BUT VARIATIONS BETWEEN CYCLES AND
MODELS WITH A LARGE ENSEMBLE SPREAD LEAVES LOW CONFIDENCE IN A
SPECIFIC SOLUTION. ENSEMBLE MEAN APPEARS TO BE THE BEST COURSE UNTIL
MODELS SETTLE.

AT THE SURFACE...A DEVELOPING LOW MOVES INTO THE GULF LATER IN
THE WEEKEND AND THEN STALLS AND SLOWLY WEAKENS. RAIN WILL CHANGE
TO SHOWERS THAT TAPER OFF IN THE NORTHERN INTERIOR EARLY IN THE
WEEK AS PRESSURES BUILD IN THE YUKON AND FLOW BECOMES MORE
NORTHERLY. THE RESULTING TROUGH ACROSS THE CENTRAL PANHANDLE SAGS
SOUTHWARD HELPING TO TAPER OFF SHOWERS IN CENTRAL SOUTHEAST ALASKA
BY MID WEEK. SOUTHERN SECTIONS WILL REMAIN CLOSE TO THE TROUGH
SO A CHANCE FOR PRECIPITATION WILL PERSIST THROUGH MOST OF THE
WEEK.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WIND ADVISORY UNTIL 6 PM AKDT THIS AFTERNOON FOR AKZ017-019-022.
         WIND ADVISORY UNTIL 4 PM AKDT THIS AFTERNOON FOR AKZ023.
         WIND ADVISORY UNTIL 9 PM AKDT THIS EVENING FOR AKZ018.
MARINE...STORM WARNING FOR PKZ022.
         GALE WARNING FOR PKZ012-013-041>043-051-052.
         SMALL CRAFT ADVISORY FOR PKZ011-021-031>036.

&&

PSS/CFD