FXAK67 PAJK 071433
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
533 AM AKST MON DEC 7 2009

.SHORT TERM...THE UPPER RIDGE OVER THE GULF CONTINUES TO PLAY A
DOMINATE ROLL IN THE WEATHER OVER THE PANHANDLE FOR THE SHORT
TERM FORECAST. CURRENTLY, MOSTLY CLOUDY TO PARTLY CLOUDY SKIES
ARE THE MAIN WEATHER FEATURE OVER MOST OF THE AREA. THE CLOUDS
ARE A RESULT OF A SHORT WAVE TROUGH MOVING SOUTH FROM THE YUKON.
FEATURE HAS LITTLE IN THE WAY OF MOISTURE AND MOST OF THE ENERGY
ASSOCIATED WITH IT IS WELL EAST OF THE AREA. STILL ENOUGH WAS
THERE FOR SOME MID TO HIGH CLOUDS AS WELL AS A FEW LOW CLOUDS TO
DEVELOP ACROSS THE AREA DURING THE NIGHT. CLOUDS SHOULD DECREASE
THIS AFTERNOON AS THE SHORT WAVE MOVES SOUTHWARD. 

 SHORT WAVE WILL CONTINUE SOUTHWARD THROUGH TODAY, EVENTUALLY
DEVELOPING A SURFACE INVERTED TROUGH OVER THE PANHANDLE BY THIS
AFTERNOON. THE INTERACTION BETWEEN THIS TROUGH AND A SLOWLY
WEAKENING HIGH IN THE CANADIAN INTERIOR WILL ONCE AGAIN FORM MORE
OUTFLOW WINDS OUT OF INTERIOR PASSES LATER THIS AFTERNOON AND
TONIGHT. FORECAST PRESSURE GRADIENT FROM PAJN TO CYXY WILL BE A
LITTLE OVER 9 MB, PAJN TO PAGY IS FORECAST TO HAVE AROUND 4 MB
DIFFERENCE, AND PAJN TO CWDL WILL BE IN THE 5.5 MB REALM. AS A
RESULT HAVE HOISTED A WIND ADVISORY FOR SKAGWAY FOR LATE THIS
AFTERNOON AND TONIGHT, AND A GALE WARNING FOR NORTHERN LYNN FOR
THE SAME TIME PERIOD. OUTFLOW WINDS WILL ALSO BE GUSTING OUT OF
OTHER INTERIOR PASSES LIKE NEAR DOWNTOWN JUNEAU, TAKU INLET, AND
OTHERS. WINDS SHOULD DIE DOWN LATE TONIGHT AS INVERTED TROUGH
DRIFTS TO THE WEST. 

 MODEL OF CHOICE CONTINUES TO BE THE NAM WITH ITS GOOD
REPRESENTATION OF THE PRESSURE GRADIENT STACKING UP ALONG THE
COAST MOUNTAINS. OTHERWISE MODEL AGREEMENT AND CONSISTENCY WAS
VERY GOOD AND FORECAST CONFIDENCE IS SOMEWHAT HIGH TODAY. 

&&

.LONG TERM...LESS MODEL AGREEMENT AND CONSISTENCY THAN LAST
NIGHT. ECMWF NOW IS MAKING THE VERY LARGE AND DEEP UPPER LOW THAT
WAS EXPECTED LATER THIS WEEK PROGRESSIVE RATHER THAN
RETROGRADE...LEAVING ONLY A WEAK TRANSIENT LOW OVER THE CENTRAL
PANHANDLE EARLY NEXT WEEK. GFS STILL MAINTAINS A DEEP RETROGRADE
FEATURE BUT PLACES IT ANYWHERE FROM THE BEAUFORT SEA TO THE GULF
OF ALASKA...DEPENDING ON THE MODEL RUN. OPTED TO NOT MAKE ANY
SUBSTANTIAL CHANGES BEYOND WEDNESDAY NIGHT. UP TO THAT
POINT...USED NAM FOR PRIMARY GUIDANCE WITH ABOVE AVERAGE
CONFIDENCE IN THE FORECAST THROUGH THAT TIME.

MAJOR TEMPERATURE TRENDS REMAIN THE SAME...WITH A SLIGHT WARM UP
THROUGH MID WEEK FOLLOWED BY COLDER AIR PRESSING IN FROM CANADA BY
NEXT WEEKEND. GUIDANCE ON DAILY HIGHS AND LOWS A BIT BETTER
TONIGHT WITH SIGNIFICANTLY LOWER DELTAS BEING PRODUCED IN CHANGE
GRIDS BY THE MATCH GUIDANCE TOOLS. RECENT PERFORMANCE BY BIAS
CORRECTED GFS MOS HAS BEEN QUITE GOOD IN THE SHORT TERM AS WELL
AS EXTENDED RANGE...SO MADE MODERATE CHANGES BASED ON THOSE
VALUES. FORECAST CONFIDENCE BETTER TONIGHT IN THIS REGARD BUT
STILL BELOW AVERAGE.

POP TREND ALSO CONSISTENT WITH LAST NIGHT WITH PRECIP IN THE FORM
OF SNOW RE-ENTERING THE FORECAST LATE IN THE WEEK. MOST LOCATIONS
WILL SEE CHANCE OR BETTER BY NEXT WEEKEND. RAIN LIMITED TO OUTER
COAST AND SOUTHERN ZONES. SNOW ELSEWHERE. PRECIP FORECAST
CONFIDENCE ABOVE AVERAGE.

SMALL CRAFT WINDS OVER SEVERAL OF THE INNER CHANNELS THROUGH
TUESDAY NIGHT AND POSSIBLY INTO WEDNESDAY MORNING. STRONGEST
NORTHERLY WINDS IN NORTHERN LYNN CANAL WITH GUSTS TO 35 KTS OUT OF
INTERIOR PASSES FORECAST CONFIDENCE IN WIND GRIDS AVERAGE. 

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WIND ADVISORY FROM 3 PM THIS AFTERNOON TO 3 AM AKST TUESDAY FOR 
     AKZ018.
MARINE...GALE WARNING FOR PKZ012. 
         SMALL CRAFT ADVISORY FOR PKZ011-013-031-035. 
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ041>043-051-052. 

&&

$$

EAL/FRITSCH