Heavy Freezing Spray Warning 1, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 AM AKST SAT DEC 31 2011

.MODEL DISCUSSION...
NUMERICAL GUIDANCE IN BETTER AGREEMENT TODAY THAN IN THE PAST FEW
DAYS. IN THE SHORT TERM THERE IS SOME DISAGREEMENT ON HOW THEY
HANDLE A LOW MOVING INTO THE GULF TODAY AND TONIGHT WITH THE GFS
A LITTLE FASTER AND FURTHER EAST THAN THE ECMWF...AND THE NAM
SOMEWHERE IN BETWEEN THEM. THE ECMWF WAS SLIGHTLY PREFERRED FOR THIS
SYSTEM. IN THE EXTENDED THE GFS AND ECMWF EACH HANDLE DIFFERENTLY
THE VARIOUS LOWS MOVING INTO THE GULF AND THE ALEUTIANS. THE ECMWF
WAS PREFERRED IN THE EARLY PORTIONS OF THE EXTENDED FORECAST WITH
THE HPC GUIDANCE USED FURTHER OUT.

.ANALYSIS AND UPPER LEVELS...
A LARGE NEARLY STATIONARY UPPER LOW IS OVER ALASKA THIS MORNING.
ANOTHER LOW OVER THE WESTERN BERING SEA IS MOVING TOWARDS THE EAST.
VERY COLD TEMPERATURES ARE SETTLED IN OVER SOUTHWEST ALASKA. OVER
SOUTH CENTRAL ALASKA TEMPERATURES ARE MODERATED SOMEWHAT BY CLOUD
COVER...WITH SOME LINGERING SNOW SHOWERS.

.SHORT TERM FORECAST...
SOUTH CENTRAL ALASKA...SNOW SHOWERS SHOULD DIMINISH FROM THE WEST
TODAY AND BE CONFINED TO PRINCE WILLIAM SOUND AND EASTWARD ALONG THE
GULF COAST BY TONIGHT AS THE SURFACE LOW WEAKENS. ANOTHER SURFACE
LOW MOVING UP FROM THE SOUTH TONIGHT WILL PUSH SNOW WESTWARD THROUGH
MONDAY BEFORE THIS SYSTEM ALSO WEAKENS AND MOVES EAST MONDAY NIGHT.

ALEUTIANS AND BERING SEA...THE LOW OVER THE WESTERN BERING SEA WILL
MOVE EAST TODAY AND THEN MERGE INTO THE WESTERN ALASKA LOW ON
SUNDAY.

SOUTHWEST ALASKA...COLD TEMPERATURES WILL CONTINUE THROUGH TONIGHT
WITH SOME MODERATION SUNDAY AND SUNDAY NIGHT AS SOME CLOUDS AND A
SLIGHT CHANCE OF SNOW MOVE INTO THE AREA ASSOCIATED WITH THE BERING
LOW.

.LONG TERM FORECAST...
MODEL GUIDANCE NOT IN VERY GOOD AGREEMENT ON THE SPECIFIC DETAILS
BUT DO AGREE THAT THE MAIN UPPER LOW WILL REMAIN IN THE VICINITY OF
WESTERN ALASKA FOR CONTINUED COLD TEMPERATURES...AND CHANCES OF
SNOW...MAINLY ALONG THE GULF COAST.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WATCH 131 THOMPSON PASS.
MARINE...GALE WARNING 129 130 132 170 172.
         HEAVY FREEZING SPRAY 121 126 127 128 129 130 132 138 140
                               141 150 160 165 179 185.
FIRE WEATHER...NONE.

LUDWIG DEC 11