Gale Warning 931, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 PM AKST SUN NOV 7 2010

.ANALYSIS AND UPPER LEVELS...
THE UPPER BLOCKING RIDGE REMAINS OVER WESTERN CANADA BUT IS STARTING
TO WEAKEN. AN UPPER TROUGH OVER WESTERN MAINLAND AND THE GULF OF
ALASKA IS BEING NUDGED EASTWARD BY AN UPPER RIDGE OVER THE EASTERN
BERING SEA. SOUTH TO SOUTHEASTERLY FLOW OVER THE GULF OF ALASKA AND
THE THE EASTERN MAINLAND HAVE PRODUCED ISOLATED SNOW SHOWERS OVER
SOUTHCENTRAL INTERIOR.

A MODERATE SURFACE LOW OVER THE NORTHERN GULF HAD KEPT RAIN AND SNOW
SHOWERS ALONG THE NORTH GULF COAST, KENAI PENINSULA AND SOUTHERN
SUSITNA VALLEY SUNDAY. A WEAK SURFACE RIDGE OVER BRISTOL BAY AND THE
SOUTHWEST ALASKAN COAST HAS REDUCED THE SNOW SHOWERS OVER SOUTHWEST
ALASKA, THE THE REGION REMAINS MOSTLY CLOUDY WITH AREAS OF FOG ALONG
THE COAST. A WEATHER FRONT OVER THE CENTRAL BERING AND CENTRAL
ALEUTIANS CONTINUES TO MOVE EAST.

.MODEL DISCUSSION...
THE MODELS ARE IN GOOD AGREEMENT OVER THE GULF AND MAINLAND ALASKA
THROUGH TUESDAY BUT ARE HAVING PROBLEMS RESOLVING THE DEVELOPMENT OF
THE COMPLEX LOW FORMING OVER THE BERING SEA OVER THE NEXT TWO DAYS.
THE EUROPEAN AND THE NAM MODELS RARE MOVING THE WEATHER FRONT A
LITTLE FASTER AND DEVELOPING A FRONTAL LOW FURTHER TO THE EAST THAN
THE GFS. THE NAM IS THE PREFERRED MODEL TODAY.

.SHORT TERM FORECAST...
SOUTHCENTRAL ALASKA...THE UPPER TROUGH OVER SOUTHWEST ALASKA AND
KODIAK ISLAND WILL MOVE OVER THE KENAI PENINSULA TONIGHT, INTO THE
SUSITNA VALLEY AND PRINCE WILLIAM SOUND MONDAY AND THE COPPER RIVER
BASIN MONDAY NIGHT. AREAS OF LIGHT SNOW OR SNOW SHOWERS WILL
ACCOMPANY THE UPPER TROUGH AS IT MOVES THROUGH THE REGION. THE
SURFACE LOW OVER THE GULF WILL REMAIN NEARLY STATIONARY AND SLOWLY
WEAKEN THROUGH THROUGH TUESDAY. RAIN AND SNOW SHOWERS ALONG THE GULF
COAST WILL GRADUALLY DIMINISH THROUGH THE PERIOD.

SOUTHWEST ALASKA...A SURFACE RIDGE OVER SOUTHWEST ALASKA WILL REMAIN
NEARLY STATIONARY AND WEAKEN THROUGH MONDAY NIGHT THEN DISSIPATE
TUESDAY. PARTIAL CLEARING OF THE CLOUDS IS EXPECTED THROUGH MONDAY
NIGHT. RAIN AND SNOW WILL MOVE INTO BRISTOL BAY AND THE KUSKOKWIM
DELTA COAST AS THE BERING SEA FRONT APPROACHES THE AREA TUESDAY.

BERING SEA...THE WEATHER FRONT OVER THE CENTRAL BERING WILL STALL
OVER THE EASTERN BERING MONDAY. A NEW FRONTAL LOW WILL DEVELOP JUST
SOUTH OF ATKA MONDAY AND WILL STRENGTHEN AS IT TURNS NORTH INTO THE
EASTERN BERING TUESDAY.

.LONG TERM FORECAST...
THE LONG TERM MODELS REMAIN IN GENERALLY GOOD AGREEMENT. THEY ALL
KEEP A COMPLEX LOW OVER THE BERING SEA AND SLOWLY WEAKENS IT THROUGH
WEDNESDAY NIGHT. A NEW LOW COMING OUT OF THE CENTRAL PACIFIC WILL
STRENGTHEN AS IT MOVES NORTH INTO THE GULF OF ALASKA BY THURSDAY.
THIS NEW LOW COULD BE STRONG ENOUGH TO PRODUCE STORM FORCE WINDS OVER
THE GULF WEDNESDAY THROUGH THURSDAY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALES 130 155 165 170 175 176
FIRE WEATHER...NONE.

NM NOV 10