Small Craft Advisory 1015, NWS Anchorage, AK

AREA FORECAST DISCUSSION...CORRECTION
SOUTHCENTRAL AND SOUTHWEST ALASKA
130 PM AKST MON DEC 14 2009

ADDED WATCH/WARNING SUMMARY...

.MODEL DISCUSSION...12Z GFS AND NAM IN GOOD AGREEMENT ON DEVELOPMENT
OF NORTH GULF LOW TONIGHT THROUGH WEDNESDAY.  COLD AIR ADVECTION OVER
SOUTHCENTRAL COMMENCES LATE THIS AFTERNOON WITH MAJOR UPPER LEVEL LOW
MOVING SOUTHWARD ACROSS THE STATE.  WIDESPREAD SNOW SHOULD DEVELOP
THIS AFTERNOON SOUTH OF THE ALASKA RANGE HOWEVER SNOWFALL AMOUNTS
TIED TO RAPID ADVANCE OF COLD DRY AIR FROM THE INTERIOR...CURRENT
THINKING IS THAT RELATIVELY QUICK CHANCE OF SNOW FOR MAT-SU AND COOK
INLET THIS EVENING BUT WITH MAIN EMPHASIS IN PRINCE WILLIAM SOUND AND
EAST.

.ANALYSIS AND UPPER LEVELS...COLD AIR STARTING TO ADVANCE SOUTHWARD
THIS AFTERNOON.  EXPECTING WESTERLY FLOW IN MID LEVELS THIS EVENING
AND DEVELOPMENT OF SURFACE LOW IN VICINITY OF PWS.

HIGH PRESSURE OVER NORTHWESTERN BERING SEA SHOULD PERSIST FOR MOST OF
THE WEEK.

.SHORT TERM FORECAST...SNOW DEVELOPING OVER SOUTHCENTRAL ZONES THIS
AFTERNOON WITH 1-3 INCHES THROUGH THIS EVENING.  AFTER 12Z IT APPEARS
THAT THE MOISTURE SUPPLY IS LIMITED SO MAINLY CLOUDS AND SNOW
TAPERING OFF IN MAT-SU AND COOK INLET...BUT SNOW DEFINITE FOR PWS
EASTWARD.  EAST WINDS ALONG NORTH GULF COAST DEVELOPING TUESDAY AND
REMAINING THROUGH WEDNESDAY.  SNOWFALL AMOUNTS FOR PWS EASTWARD
SUBSTANTIAL.

SOME SNOW THIS AFTERNOON AND EVENING FOR EASTWARD REGIONS OF ZONES
152 AND 161 BUT MAINLY TURNING COLD OVER NIGHT. CLEAR AND COLD FOR
REMAINDER OF SOUTHWEST ZONES.

STRATUS AND ISOLATED RAIN OR SNOW SHOWERS WILL BE THE NORM FOR MOST
OF THE GREATER BERING REGION.

.LONG TERM FORECAST...UPPER LEVEL LOW IS PROGGED BY GFS TO REMAIN
OVER WESTERN INTERIOR THROUGH LATE IN THE WEEK...SURFACE LOW MOVES
INTO THE YUKON ON THURSDAY.  HENCE PARTLY TO MOSTLY CLOUDY FROM WEST
TO EAST.  PLENTY OF SUBZERO TEMPS...COLDEST IN THE WEST WARMER IN THE
EAST.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...HEAVY FREEZING SPRAY WARNING...130 138 150 160 180 185
         GALE WARNING...130
FIRE WEATHER...NONE

JMP DEC 09