Small Craft Advisory 553, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKDT SUN AUG 7 2011

.MODEL DISCUSSION...500 MB HT AND MSLP MODEL INITIALIZATIONS ARE
REASONABLE AS WELL AS FORECAST TREND THROUGH WED AFTERNOON FOR MUCH
OF THE MAINLAND AND EASTERN BERING SEA. MODELS ARE STRUGGLING SOME
WITH THE REMNANTS OF A TYPHOON HEADING TOWARD THE WESTERN ALEUTIANS
WED. THE GFS/ECMWF APPEAR TO BE IN GENERALLY GOOD AGREEMENT WITH THIS
FEATURE WITH THE NAM AS THE OUTLIER. GRIDS IN THE EAST DOMAIN WILL BE
FRESHENED WITH THE NAM. THE NAM IS ALSO OK OUT WEST THROUGH ABOUT 60
HRS...THEN WILL TREND TOWARD THE GFS SOLUTION.

.ANALYSIS AND UPPER LEVELS...
.500MB...A SHORT WAVE TROUGH EXTENDING FROM A LOW CENTER OVER THE
CENTRAL INTERIOR THIS MORNING LIFTS NORTHWARD AND WEAKENS. THE LONG
WAVE OVER EASTERN RUSSIA DIGS OVER WESTERN AK MON AFTERNOON AND
EVENING AND SETS UP A BROAD W-SW FLOW ACROSS MUCH OF THE SOUTHERN
MAINLAND. THE LONG WAVE MOVES TO THE SE MAINLAND/EASTERN GULF AROUND
140W WED AFTERNOON WITH A LOW WEST OF YAKUTAT. ON THE
BACKSIDE...NORTHWESTERLY FLOW SETS UP OVER THE REMAINDER OF THE
MAINLAND AS THE RIDGE BUILDS OVER THE EASTERN BERING SEA. A FAIRLY
COMPACT LOW CENTER...ASSOCIATED WITH THE REMNANTS OF A
TYPHOON...MOVES TO THE FAR WEST ALEUTIAN ISLANDS WED AFTERNOON.

.SURFACE...
A WEATHER FRONT ASSOCIATED WITH A COLD UPPER TROUGH HAS MOVED TO THE
EASTERN MAINLAND THIS MORNING. STEADY RAIN...AND A LITTLE SNOW AT
HIGHER ELEVATIONS...ASSOCIATED WITH THIS FEATURE HAS BEEN REPLACED BY
SHOWERS WITH A TROUGH TO ITS WEST. FURTHER WEST...A FRONTAL TROUGH
APPROACHING SW ALASKA THIS AFTERNOON MOVES INTO EASTERN BRISTOL BAY
MON EVENING THEN INTO SOUTHCENTRAL AND THE WESTERN GULF OF ALASKA
TUE.

.SHORT TERM FORECAST...
.SOUTHCENTRAL ALASKA...WINDY CONDITIONS ACROSS THE NORTHERN GULF AND
COPPER RIVER BASIN WILL DIMINISH THROUGH THIS EVENING. UPPER SHORT
WAVES MOVING ACROSS THE REGION WILL CONTINUE THE THREAT OF SHOWERS
THROUGH MON. PRECIPITATION WILL BECOME MORE ORGANIZED AND STEADY
ACROSS MUCH OF THE REGION MON NIGHT AND TUE AS A WEATHER FRONT MOVES
IN FROM THE WEST. PRECIPITATION SHOULD TAPER OFF SIGNIFICANTLY WED AS
DRIER CONDITIONS MOVE IN FROM THE WEST AFTER FRONTAL PASSAGE AND THE
ONSET OF NORTHERLY FLOW ALOFT.

.SOUTHWEST ALASKA...
A WEATHER FRONT APPROACHING THE KUSKOKWIM DELTA THIS AFTERNOON WILL
SPREAD RAIN ACROSS THE REGION AS IT MOVES TO EASTERN BRISTOL BAY MON
NIGHT. RAIN SHOULD BE TAPERING OFF FROM THE WEST MON NIGHT AND TUE AS
HIGH PRESSURE BUILDS ACROSS THE EASTERN BERING SEA. FOG WITH LOW
STRATUS LIKELY ACROSS COASTAL AREAS/NORTHERN AK PEN MON NIGHT AND TUE
WITH MORE CLOUD BREAKS INLAND.

.BERING SEA...ALEUTIANS...A WEAK RIDGE WILL KEEP MUCH OF THE ALEUTIAN
ISLANDS DRY INTO THE EARLY PART OF THIS WEEK. SHOWERS WILL CONTINUE
ACROSS THE NORTH BERING AS A SERIES OF UPPER WAVES PROGRESS ACROSS
THE REGION.  SOUTHERLY WINDS WILL INCREASE ACROSS MUCH OF THE CENTRAL
AND WESTERN ALEUTIANS TUE NIGHT AND WED WITH THE APPROACH OF THE
REMNANTS OF AN OLD TYPHOON. A WEATHER FRONT ASSOCIATED WITH THIS
FEATURE SPREADS RAIN ACROSS THE WESTERN/CENTRAL ALEUTIANS TUE.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.

RMC AUG 11