Small Craft Advisory 1102, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 PM AKST MON DEC 20 2010

.ANALYSIS AND UPPER LEVELS...
A SURFACE LOW REMAINS OVER THE NORTHERN GULF OF ALASKA WITH A
WEAKENING OCCLUDED FRONT OVER WESTERN PRINCE WILLIAM SOUND, THE
ANCHORAGE BOWL AND THE LOWER SUSITNA VALLEY. SNOW FELL MAINLY ALONG
THE FRONT THROUGH MONDAY AFTERNOON. ANOTHER MODERATE LOW OVER THE
SOUTHWEST BERING SEA WITH AN OCCLUDED FRONT ACROSS THE SOUTHERN
BERING SEA CONTINUES TO MOVE EAST.

THE UPPER LOW OVER SOUTHWEST ALASKA CONTINUES TO SLIDE INTO THE GULF.
THE UPPER RIDGE OVER THE EASTERN BERING WILL FLATTEN AS ANOTHER UPPER
LOW OVER THE WESTERN BERING MOVES THROUGH IT TONIGHT.

.MODEL DISCUSSION...
MODELS ARE IN GOOD AGREEMENT THROUGH WEDNESDAY NIGHT. THE NAM DOES A
BETTER JOB OVER SOUTHCENTRAL ALASKA WHILE THE GFS IS PREFERRED OVER
THE SOUTHWEST MAINLAND AND THE BERING SEA.

.SHORT TERM FORECAST...
SOUTHCENTRAL ALASKA...THE OCCLUDED FRONT, FROM WESTERN PRINCE WILLIAM
SOUND THROUGH THE SOUTHERN SUSITNA VALLEY, WILL DISSIPATE THIS
EVENING. THE LOW OVER NORTHERN GULF WILL MOVE SOUTH AND DISSIPATE
SOUTH OF KODIAK ISLAND TUESDAY NIGHT. ANOTHER LOW WILL FORM SOUTH OF
THE GULF TUESDAY NIGHT. COLD, DRY AIR OVER THE CENTRAL INTERIOR WILL
SPREAD SOUTH INTO THE COPPER RIVER BASIN THROUGH WEDNESDAY AND WILL
STRENGTHEN THE PRESSURE GRADIENT ALONG THE GULF COAST. GUSTY WINDS
WILL CONTINUE TO BLOW THROUGH CHANNELED TERRAIN ALONG THE CHUGACH
MOUNTAINS THROUGH WEDNESDAY NIGHT. SKIES WILL SLOWLY CLEAR FROM THE
NORTH LATE TONIGHT AND TUESDAY.

SOUTHWEST ALASKA...THE SCATTERED SNOW SHOWERS WILL END THIS EVENING
AS THE UPPER LOW MOVES INTO THE GULF LATE TONIGHT AND TUESDAY. SKIES
WILL BECOME MOSTLY CLEAR BY TUESDAY NIGHT AS BOTH A SURFACE AND UPPER
RIDGE MOVES INTO THE EASTERN BERING.

BERING SEA...THE LOW OVER THE SOUTHWESTERN BERING WILL MOVE EAST AND
DISSIPATE OVER THE EASTERN ALEUTIANS TUESDAY MORNING. RAIN AND SNOW
ALONG THE CENTRAL AND EASTERN ALEUTIANS AND THE ALASKA PENINSULA WILL
BECOME SNOW SHOWERS TUESDAY. A SURFACE RIDGE BUILDING OVER THE
WESTERN BERING TONIGHT WILL MOVE EAST INTO THE EASTERN BERING
WEDNESDAY.

.LONG TERM FORECAST...
THE RIDGE OVER THE EASTERN BERING WILL MOVE INTO WESTERN ALASKA
THURSDAY THEN WILL DISSIPATE AS A WEATHER FRONT OVER SIBERIA MOVES
ONTO THE WESTERN ALASKA COAST THURSDAY NIGHT. THE FRONT WILL
DISSIPATE FRIDAY. AREA OF SNOW WILL DEVELOP THE KUSKOKWIM DELTA,
WESTERN BRISTOL BAY AND THE ALASKA PENINSULA LATE THURSDAY THROUGH
FRIDAY MORNING. A COMPLEX LOW WILL REMAIN SOUTH OF THE GULF THROUGH
FRIDAY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 130 132 150 155 160 165 170 172 175 176 180
FIRE WEATHER...NONE.

NM DEC 10