Small Craft Advisory 929, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKST FRI NOV 22 2013

.ANALYSIS AND UPPER LEVELS...
THERE IS A LARGE UPPER LEVEL LOW CENTERED OVER THE KUSKOKWIM DELTA.
THERE IS A SMALLER UPPER LOW SOUTH OF THE CENTRAL ALEUTIANS. A
FRONTAL SYSTEM IS DRAPED EAST TO WEST ACROSS SOUTHERN ALASKA WITH A
SURFACE LOW CENTERED OVER THE SUSITNA VALLEY.

.MODEL DISCUSSION...
THE NUMERICAL MODELS ARE IN FAIRLY GOOD AGREEMENT...WITH THE
EXCEPTION OF THE NAM. THE NAM QUICKLY BECOMES A BIT OF AN OUTLIER
AND THUS WAS NOT USED FOR THE AFTERNOON FORECAST. THE GFS AND ECMWF
WERE THE PREFERRED MODELS AND SHOW GOOD AGREEMENT THROUGH 84 HOURS.

.SHORT TERM FORECAST...
FOR SOUTH CENTRAL ALASKA...THE FRONTAL SYSTEM AND ASSOCIATED SURFACE
LOW WILL MOVE NORTH THROUGH TONIGHT AND EXIT NORTH OF THE AREA
SATURDAY MORNING. COLD AIR WILL COME SURGING INTO THE AREA
TONIGHT...WITH A BURST OF SNOW FOR MOST AREAS WITH THE ARRIVAL OF
THE FRONT. MOST OF SOUTH CENTRAL ALASKA WILL REMAIN IN CYCLONIC FLOW
THROUGH SATURDAY EVENING AS THE MAIN UPPER LOW (CURRENTLY OVER THE
KUSKOKWIM DELTA) DRIFTS NORTHEAST ACROSS THE STATE. ON SATURDAY
NIGHT AND SUNDAY MOISTURE WILL INCREASE OVER SOUTH CENTRAL ALASKA AS
THE LOW CURRENTLY SOUTH OF THE ALEUTIANS MOVES INTO THE BERING SEA
AND THE WARM FRONT PUSHES INTO THE AREA FROM THE SOUTH. CONDITIONS
WILL DRY OUT SUNDAY NIGHT AND MONDAY AS THE WARM FRONT DISSIPATES
AND HIGH PRESSURE BUILDS IN FROM THE SOUTHEAST.

FOR SOUTHWEST ALASKA...THE KUSKOKWIM LOW WILL SLOWLY SLIDE THROUGH
SOUTHWEST ALASKA THROUGH SATURDAY AFTERNOON THEN EXIT TO THE
NORTHEAST. PLENTY OF COLD AIR AND MOISTURE WILL KEEP SNOW/SNOW
SHOWERS OVER THE AREA. AS THE ALEUTIAN LOW SLIDES INTO THE BERING
SEA ON SUNDAY AND MONDAY MORE MOISTURE WILL PUSH NORTH. TEMPERATURES
WILL WARM ALSO AS 500 MB HEIGHTS INCREASE AND WARMER AIR AT ALL
LEVELS PUSHES NORTH INTO THE AREA.

FOR THE BERING SEA AND ALEUTIANS...GENERALLY CYCLONIC FLOW ALOFT
WILL CONTINUE OVER THE BERING SEA AS THE LOW CURRENTLY OVER THE AREA
(THE KUSKOKWIM DELTA LOW) IS REPLACED BY THE BERING LOW. THIS WILL
ALLOW SHOWERY WEATHER TO CONTINUE FOR MOST OF THE AREA THROUGH
MONDAY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE WARNING 160 165 174 176 177 178 180 181 185.
         HEAVY FREEZING SPRAY 181 185.
FIRE WEATHER...NONE.

LUDWIG NOV 13