Small Craft Advisory 1099, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AST WED NOV 29 2006

.DISCUSSION...

GFS...NAM...AND UKMET IN GOOD AGREEMENT WITH EACH OTHER OUT THROUGH
60 HOURS BUT THERE IS LITTLE CONSISTENCY BETWEEN RUNS. GFS IS
PREFERRED MODEL...ESPECIALLY FOR THE BERING...BUT OVERALL CONFIDENCE
IS NOT HIGH. CONFIDENCE VERY LOW BEYOND 96 HOURS.

AT 500 MB THERE ARE THREE MAIN FEATURES.
1...A SMALL CUT OF CENTER OVER THE NORTHERN GULF OF ALASKA. LOW IS
FORECAST TO MOVE OFF RAPIDLY EASTWARD INTO CANADA.
2...A STRONG LOW ANCHORED OVER EASTERN RUSSIA. W-SW UPPER LEVEL
STEERING FLOW WILL HOLD THROUGH AT LEAST 72 HOURS OVER THE BERING
SEA.
3...A TRANSIENT RIDGE THAT DEVELOPS OVER SOUTHWEST ALASKA TODAY AND
MOVES INTO WESTERN CANADA FRIDAY.

WEST OF 165W...
IMPRESSIVE 981 MB LOW NEAR ATKA HAS PLENTY OF WARM ADVECTION ALONG
ITS FRONTSIDE AND STRONG COLD ADVECTION ON ITS BACKSIDE. RAIN...HEAVY
AT TIMES...IS EXPECTED TODAY ALONG THE EASTERN ALEUTIANS TODAY AND
THE ALASKA PENINSULA TONIGHT. AS WINDS SHIFT FROM SOUTH TO NORTHWEST
ALONG THE CENTRAL ALEUTIANS TODAY AND EASTERN ALEUTIANS TONIGHT
EXPECT THE RAIN TO TURN QUICKLY TO SNOW SHOWERS. HIGH WIND WATCH FOR
NORTHWEST WINDS OVER THE CENTRAL ALEUTIANS HAS BEEN UPGRADED TO
WARNING.

165W TO 155W...CONFIDENCE LOWEST FOR THIS REGION.
OOZ WED RUN OF GFS MOVES THE LOW NEAR ATKA TO 45 NM SOUTH OF MEKORYUK
BY WED EVENING AND THEN INTO THE NORTHERN CHUKCHI SEA BY THU EVENING.
IN COMPARISON...YESTERDAYS GFS WANTED TO MOVE IT INTO BRISTOL BAY.
LEFT THE HIGH WIND WATCH FOR EASTERN ALEUTIANS AS A WATCH.
ALSO A NEW 991 MB LOW IS EXPECTED TO DEVELOP ALONG THE FRONT APPROX
90 NM SOUTHWEST OF DUTCH HARBOR THIS AFTERNOON. MODELS ARE NOT
CAPTURING THIS FEATURE WELL...EXACT POSITION WILL DIRECTLY AFFECT
WIND AND PRECIP FORECAST FOR ALASKA PENINSULA TOMORROW.

EAST OF 155W...
THE 989 MB LOW IN NORTHERN GULF OF ALASKA...REFLECTION OF UPPER LEVEL
FEATURE...IS PROGGED TO MOVE OFF RAPDIDLY SOUTHEASTWARD. NOT MUCH
PRECIP AFTER ALL WITH THIS SYSTEM. DRY OFF CONTINENT FLOW WILL
PERSIST THROUGH TONIGHT. GUSTY NORTHEAST TO NORTHWEST WINDS THROUGH
CHANNELED AREAS OF THE NORTH GULF COAST WILL QUICKLY DIMINISH THIS
MORNING. INCREASING CLOUDS AND A CHANCE OF PRECIP BEGINNING TOMORROW
MORNING AS MAJOR SYSTEM OUT WEST APPROACHES.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...HIGH WIND WARNING 187
         HIGH WIND WATCH 185
MARINE...GALE 132 150 155 160 165 171 175 176 179 180 185
         STORM 170 172
         HEAVY FREEZING SPRAY 185
FIRE WEATHER...NONE.

ASB NOV 06