Wind Advisory 100, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
105 PM AKST THU DEC 11 2008

.SHORT TERM...500MB RIDGE BUILDING IN FROM THE NORTHWEST OVER
THE SE PANHANDLE TODAY AND TONIGHT AS BAROCLINIC ZONE CONTINUES
TO MOVE SE OUT OF THE AREA. 1040MB HIGH PRESSURE BUILDS IN FROM
THE NORTHWEST THIS AFTERNOON WITH INVERTED TROF OVER THE NORTHERN
PANHANDLE. EXPECT RAIN AND SNOW SHOWER ACTIVITY TO CONTINUE TO
MOVE IN FROM THE WEST ACROSS THE NORTHERN AND CENTRAL PANHANDLE
THIS AFTERNOON. THE STRATIFORM PRECIPITATION WILL TRANSITION TO
SHOWER ACTIVITY IN THE SOUTHERN PANHANDLE THIS AFTERNOON AND
TONIGHT. SHOWER ACTIVITY SHOULD DIMINISH LATER THIS AFTERNOON IN
NORTHERN ZONES AND LATER TONIGHT IN SOUTHERN ZONES. COLDER AND
DRIER WEATHER FOR FRIDAY WITH OCCASIONAL PEEKS OF THE SUN FOR THE
NORTHERN AND CENTRAL PANHANDLE FRIDAY. LOCALLY BREEZY CONDITIONS
IN SOUTHERN ZONES ON FRIDAY AS THE GRADIENT INCREASES BETWEEN THE
HIGH IN THE YUKON AND A RAPIDLY DEVELOPING LOW IN THE NORTHERN
PACIFIC.

12Z GFS WAS THE MODEL OF CHOICE FOR THE TONIGHT AND TOMORROW
PERIODS AND PROVIDED A SMOOTH TRANSITION TO LONG TERM PERIODS.
MADE ONLY MINOR CHANGES TO POP FIELDS AND TEMP FIELDS TO FINE
TUNE TIMING ON FRONTAL PASSAGE THROUGH THE PANHANDLE.

.LONG TERM...
THE AXIS OF A 500 MB RIDGE OVER THE NORTH PACIFIC WILL ROTATE
EASTWARD BEGINNING FRI NIGHT AND ACROSS THE NORTHERN GULF THROUGH
MON. THIS WILL HELP PROVIDE OFFSHORE FLOW ACROSS THE PANHANDLE
ALLOWING FOR DRY CONDITIONS THROUGH EARLY NEXT WEEK. THE
INVERTED SFC TROF MENTIONED ABOVE WILL ESTABLISH ITSELF ALONG THE
OUTER COAST BY SAT MORNING. THIS IN TURN WILL LEAD TO A STRONG
PRESSURE GRADIENT AS THE HIGH OVER THE YUKON BUILDS TO 1050 MB.
COLD AIR AND BLUSTERY CONDITIONS WILL BE THE RESULT OF THIS
PROCESS THROUGH SUN BEFORE WARMER TEMPERATURES AND THE GRADIENT
WEAKEN MON.

FORECASTER CONFIDENCE IS HIGH THROUGH EARLY NEXT WEEK WITH A
GRADUAL DECLINE BY THE END OF THE FORECAST PERIOD. THE GFS HAS
BEEN CONSISTENT THE PAST FEW RUNS WITH THE 12Z RUN CONTINUING THE
TREND. THIS WAS FURTHER AFFIRMED AFTER CONSULTING WITH PAFC. AS A
RESULT...USED THE 12Z GFS TO REFRESH THE GRIDS WITH NO
SIGNIFICANT CHANGES BEING NOTED.

NEXT WEEK WILL BEGIN WITH TEMPERATURES REBOUNDING AS WARM AIR
MOVES IN ALONG THE UPPER RIDGE AXIS. A LOW WILL MOVE UP FROM THE
NORTH PACIFIC AND OVER THE TOP OF THE RIDGE BRINGING A CHANCE OF
PRECIPITATION BACK TO THE FORECAST BY THE END OF THE WEEK.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ041>043-051-052.

CCC/MAM