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FXAK67 PAJK 251439
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
539 AM AKST SUN JAN 25 2015

.SHORT TERM...AS THE STORM FORCE LOW THAT BROUGHT STRONG WINDS
ACROSS MUCH OF THE SOUTHERN PANHANDLE HAS MOVED ONSHORE, A RIDGE
IS BUILDING OVER THE PANHANDLE IN ITS WAKE. THE TIGHTENING
PRESSURE GRADIENT BETWEEN THE RIDGE AND THE LEE SIDE TROUGHING ON
THE CANADIAN SIDE HAS STRENGTHENED THE GRADIENT TO AROUND -5 MB
BETWEEN JUNEAU AND SKAGWAY EARLY THIS MORNING. THIS WILL RESULT IN
SOLID GALE FORCE WINDS THROUGH THE CANAL. JUNEAU MAY BE A BIT
BREEZY EARLY OWING TO THE SAME PHENOMENON, BUT THE
SUPPORTING LOW LEVEL JET FROM THE SOUTHWEST MAY NOT YIELD THE
GREATEST SETUP FOR STRONG WIND GUSTS. THEREFORE, HAVE JUST 15 TO
25 MPH DIMINISHING THROUGH THE DAY HERE. SITKA DEFINITELY SAW A
QUICK ACCELERATION OF STRONG WEST WINDS...GUSTING TO 45 MPH...WITH
THE SECOND WRAP OF THE STORM, BUT HAS SINCE RELAXED TO 10 TO 20
MPH AT MOST. WRANGELL`S AND CAPE DECISION`S WINDS INDICATE THAT
THERE ARE STILL SOME SOLID SOUTHWESTERLIES PUSHING THROUGH THE
CENTRAL PANHANDLE WITH EVEN PETERSBURG FEELING A BIT BREEZY FOR
THEM FROM THE SOUTHWEST. SO STARTED THINGS OFF A LITTLE STRONGER
THAN SOME OF THE AIRPORT OBSERVATIONS FOR ZONES 27/28 EARLIER TO
DIMINISH THROUGH THE DAY. WINDS WILL LESSEN IN THE AFTERNOON FOR
MOST OF THE ENTIRE CWA. SKAGWAY THOUGH WILL GUST TO 45 MPH THROUGH
MID-AFTERNOON BEFORE BEGINNING TO FALL SLIGHTLY OVERNIGHT. 700 MB
WINDS ARE JUST TOO STRONG TO RELAX COMPLETELY. IN ADDITION MOS
GUIDANCE KEEPING THINGS FRISKY OVERNIGHT. BY LATE TONIGHT, THINGS
COULD FALL FLAT CALM PARTICULARLY OVER THE SOUTHERN ZONES.

THE OTHER STORY IS THE COOLING CONDITIONS PUSHING THROUGH FROM THE
WEST. AN AIR MASS CHANGE WILL BE UNSTABLE ENOUGH AND CHILLY ENOUGH
TO SUPPORT A MIX OF SNOW IN YAKUTAT TODAY, ESPECIALLY IN STRONGER
SHOWERS. A LITTLE SNOW MAY ALSO MIX IN NEAR HAINES/SKAGWAY LATE
THIS AFTERNOON AS WELL. BUT GIVEN SUCH STRONG SOUTHERLIES, THE
LIKELIHOOD OF THIS HAPPENING IS PROBABLY NOT GREAT. SHOWERS WILL
DIMINISH IN INTENSITY...ESPECIALLY AFTER A VORTICITY LOBE PASSES
OVER THE NORTH LATE THIS AFTERNOON...AND THINGS WILL BEGIN TO DRY
OUT. TEMPERATURES WILL BE COOL ENOUGH TO SUPPORT SNOW FROM NORTH
OF SITKA TO JUNEAU OVERNIGHT TONIGHT. BUT ANY ACCUMULATIONS SHOULD
BE VERY MINOR. SNOW LEVELS MAY BRIEFLY CLIMB TO 2500 FEET OVER
MUCH OF THE CENTRAL PANHANDLE TODAY, BUT THEN FALL TO 1000 TO 1500
FEET THIS AFTERNOON. THEY WILL IN TURN FALL TO SEA LEVEL
OVERNIGHT...NORTH OF SITKA/ANGOON. HYDER SHOULD REMAIN ALL RAIN
AS IT WILL TAKE TIME FOR THE SNOW LEVEL TO FALL HERE WITHOUT A
GOOD SURGE OF COLD AIR FROM THE CANADIAN SIDE. TEMPERATURES SHOULD
FALL CLOSE TO FREEZING FOR THE NORTH CENTRAL PANHANDLE...AND INTO
THE 20S FOR LYNN CANAL AND YAKUTAT. THE SOUTH WILL FALL INTO THE
30S. THIS WILL FEEL SIGNIFICANTLY COOLER THAN THE LAST WEEK.
TEMPERATURES TODAY PROBABLY WILL NOT CLIMB MUCH THROUGH THE DAY,
AND MAY BEGIN TO CHILL A LITTLE IN THE LATE AFTERNOON.

USED ARW, NMM, ECMWF, AND NAM FOR SMALL UPDATES. CONFIDENCE IN
FORECAST GOOD.


.LONG TERM...RESIDUAL TROUGH ALONG THE GULF COAST INTO THE
SOUTHERN YUKON TO HOLD ON BUT WEAKEN THROUGH EARLY MONDAY WHILE A
WEAK AREA OF HIGH PRESSURE BUILDS OVER THE GULF OF ALASKA. A WEAK
LOW WILL BE PULLING NORTH MONDAY AND LOOKS TO MOVE OVER HECATE
STRAIT AND INTO BRITISH COLUMBIA JUST SOUTH OF THE PANHANDLE THIS
WILL KEEP A LITTLE LITE PRECIPITATION ACROSS THE SOUTHERN
PANHANDLE EARLY IN THE WEEK HOWEVER WILL MAINLY BE RESPONSIBLE FOR
TIGHTENING THE PRESSURE GRADIENT ACROSS THE NORTHERN PANHANDLE.

THE BROAD AREA OF LOW PRESSURE SOUTH OF THE EASTERN ALEUTIANS AND
ALASKA PENINSULA WILL PERSIST THROUGH THE EARLY PORTION OF THE
WEEK WITH A COUPLE OF SHORT WAVES ROTATING ABOUT THE FEATURE UNDER
THE LONG WAVE TROUGH ALOFT EXTENDING SOUTH FROM THE EASTERN HALF
OF THE BERING SEA INTO THE NORTH CENTRAL PACIFIC. MEANWHILE AN
UPPER LEVEL RIDGE WILL POSITION ALONG ALONG OR JUST EAST OF THE
PANHANDLE. DO EXPECT A SHORT WAVE TO PUSH OVER SOUTHEAST ALASKA
LATE TUESDAY AND THIS SEEMS TO CORRESPOND WITH A SURFACE FRONT
HEADED NORTH OVER THE EASTERN GULF OF ALASKA...RETURNING WARMER
AIR TO THE CENTRAL GULF COAST BY MIDWEEK. THE ASSOCIATED SURFACE
LOW STAYS WEST OF 150 WEST.

LONG TERM MODELS FEATURES SUGGESTING A FAIRLY ORGANIZED LOW TO
DEVELOP AS IT MOVES OUT OF THE CENTRAL PACIFIC INTO THE GULF
HEADED TO THE LATER PART OF THE WEEK. WILL HAVE TO SEE IF LONG
RANGE GUIDANCE PICKS UP ON THIS WHEN WE GET IT LATER TODAY.

FORECAST CONFIDENCE IS AVERAGE TO ABOVE AVERAGE INTO THE EARLY
PORTION OF THE WEEK. ONLY SOME MINOR CHANGES TO THE FORECAST EARLY
ON... WITH AVERAGE CONFIDENCE FOR LATER PERIODS.


&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND UNTIL 3 PM AKST THIS AFTERNOON FOR AKZ018.
MARINE...GALE WARNING FOR PKZ012-031.
         SMALL CRAFT ADVISORY FOR PKZ011-013-021-022-032>036-041>043-051-
     052.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ053.

&&

$$

JWA/BEZENEK

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