FXAK67 PAJK 062203
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
102 PM AKST SUN DEC 6 2009

.SHORT TERM...FILTERED SUNSHINE UNDER STRONG RIDGE DOMINATES THE
WEATHER OVER THE PANHANDLE. MOST LOCATIONS AT VFR CONDITIONS WITH
THE EXCEPTION OF PAGS WHICH IS AT MVFR FOR CIGS. WINDS HAVE
DIMINISHED TODAY AS THE 1056 MB HIGH IN THE YUKON HAS MOVED
SOUTHEAST INTO CENTRAL BC. A WEAK SHORTWAVE IS MOVING OVER THE
RIDGE BRINGING A CIRRUS SHIELD OVER NORTHERN PORTIONS OF THE
PANHANDLE. MID AND HIGH CLOUD DECKS SHOULD MODERATE LOW
TEMPERATURES TONIGHT WITH THERMAL TRAPPING IN THE NORTHERN ZONES
HOWEVER SOUTHERN ZONES SHOULD REMAIN MOSTLY CLEAR WHICH WILL
ALLOW FOR EFFICIENT RADIATIONAL COOLING AND ANOTHER CHILLY NIGHT.
DEW POINT DEPRESSIONS STILL REMAIN SMALL ACROSS THE PANHANDLE AND
WITH LIGHT WINDS UNDER A WEAK INVERSION PATCHY FOG IS POSSIBLE
ESPECIALLY IN AND NEAR THE INNER CHANNELS AND LOCATIONS THAT
REMAIN CLOUD FREE TONIGHT. 

 MODEL AGREEMENT REMAINS GOOD THROUGH THE SHORT TERM WITH
NAM12 AGAIN HANDLING WHAT REMAINS OF GAP FLOWS ASSOCIATED WITH
THE GRADIENT BETWEEN THE PANHANDLE AND THE 1056 MB HIGH IN BC THE
BEST. POPS REMAIN NIL ACROSS THE PANHANDLE THROUGH MONDAY.
SHORTWAVE MOVING SOUTH OUT OF THE YUKON AND INTO BC THIS EVENING
WILL INCREASE MID AND HIGH CLOUDS BUT NO PRECIP EXPECTED.
FORECAST CONFIDENCE IS ABOVE AVERAGE. 

&&

.LONG TERM...UPPER LVL RIDGE REMAINS THE MAIN INFLUENCE OVER THE
FORECAST AREA THROUGH MID WEEK. THROUGH THAT TIME EXPECTING
MOSTLY SUNNY SKIES AND DRY CONDITIONS WITH COLD TEMPERATURES TO
PERSIST. AS THE RIDGE RETROGRADES WEST A POLAR VORTEX WILL TRACK
ACROSS CANADA INTO THE AK INTERIOR BY THE END OF NEXT WEEK. STILL
SOME QUESTION ON ITS FINAL LOCATION. SURFACE HIGH WILL MOVE DOWN
FROM YUKON OVER BC WITH AN INCREASE EAST WEST PRESSURE GRADIENT.
EXPECTING BREEZY CONDITIONS OVER THE N ZONES TO DIMINISHING
THROUGH MON NIGHT WITH SMCR WINDS OVER N AND S LYNN CANALS.
INTERIOR PASSES WILL HAVE GUSTY WINDS BUT SHOULD BE LOCALIZED.
NEXT CHANCE OF PRECIP WILL BE TOWARDS THE END OF THE
WEEK...STARTING OVER THE SOUTHERN ZONES AND MOVING NORTH. PRECIP
WILL BE MOSTLY SNOW WITH A MIX OF RAIN TO THE SOUTH BUT AMOUNTS
ARE STILL UNCERTAIN. STILL UNCERTAIN ARE TEMPERATURES ARE MODES
ARE IN FAIR DISAGREEMENT. GUIDANCE STILL SHOWING LARGE VARIATIONS
WITH ENSEMBLE MEAN SHOWING A LARGE DIFFERENCE. LIMITED ANY
TEMPERATURE CHANGES.

MODELS STARTED OFF IN GOOD AGREEMENT. STARTED WITH A BLEND OF
NAM12 AS IT GAVE A BIT MORE DETAIL IN PRESSURE GRADIENT AND TO
BLEND WITH THE SHORT TERM. GFS SOLUTION NOW MORE IN LINE WITH THE
EC ON THE POLAR LOW TRACK MOVING INTO THE AK INTERIOR. ITS FINAL
LOCATION COMPARED TO THE MORE SOUTHERN EC SEEMED A BIT MORE
REALISTIC. USED A BLEND OF HPC GUIDANCE AND GFS 12Z BLEND WITH
INHERITED GRIDS FOR THE REMAINDER OF THE LONG TERM.

FORECAST CONFIDENCE FOR WIND AND POPS ARE ABOVE AVERAGE WITH
TEMPERATURE FORECAST CONFIDENCE STILL LOW.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ011>013-031. 
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ043-051-052. 

&&

$$

CCC/PRB