Gale Warning 1002, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 PM AKST SUN DEC 12 2010

.ANALYSIS AND UPPER LEVELS...
VERY LITTLE CHANGE SINCE YESTERDAY IN THE OVERALL WEATHER PATTERN
ACROSS THE REGION. A STACKED HIGH PRESSURE SYSTEM CONTINUES TO REIGN
OVER THE CENTRAL BERING. A WEAKENING 90 KT JET ROUNDS THIS RIDGE AND
TRACKS ACROSS THE NORTHERN INTERIOR BEFORE CURVING WESTWARD OVER
SOUTHWEST ALASKA AND THE AKPEN. OVER THE EASTERN HALF OF THE
STATE...AN UPPER LEVEL TROUGH IS SLOWLY ADVANCING EASTWARD AS A
SHORTWAVE RIDGE ROUNDS THE TOP OF THE BERING SEA HIGH AND DIVES
SOUTHWARD INTO SOUTHWEST AND SOUTHCENTRAL ALASKA. THE REGION WAS
TREATED TO A CLEAR AND CRISP MORNING TODAY AS DRY NORTHERLY FLOW
DEVELOPED OUT AHEAD OF THIS RIDGE.

.MODEL DISCUSSION...
MODELS CONTINUE TO BE IN VERY GOOD AGREEMENT GIVEN THE STABLE WEATHER
PATTERN IN PLACE. THE MODELS HAVE COME INTO MUCH BETTER AGREEMENT
REGARDING THE SHORTWAVE TROUGH THAT TRACKS OVER SOUTHWEST ALASKA
MONDAY AFTERNOON...THOUGH THE NAM IS STILL SLIGHTLY WEAKER THAN THE
EC AND GFS. MODELS ALSO CONTINUE TO BE ON TRACK WITH THE ARCTIC LOW
THAT PLUNGES SOUTHWARD THROUGH THE COPPER RIVER BASIN AND INTO THE
NORTH GULF BY WEDNESDAY MORNING. THE ONLY REAL DIFFERENCE IS THAT THE
EC DEPICTS A CLOSED UPPER LEVEL LOW WHILE THE GFS MAINTAINS IT AS A
SHORTWAVE TROUGH. IT IS ALSO INTERESTING TO NOTE THAT THE UKMET
TRACKS THE LOW MUCH FURTHER WEST THAN THE OTHER MODELS...BRINGING IT
OVER THE COOK INLET REGION INSTEAD. HOWEVER...THIS SOLUTION WAS
CONSIDERED AN OUTLIER AND WAS NOT USED. TODAY'S FORECAST LEANED
TOWARDS THE GFS WITH THE NAM USED FOR DETAILS.

.SHORT TERM FORECAST...GRADIENT HAS BEEN STRONG ENOUGH TO DISCOURAGE
THE DEVELOPMENT OF WIDESPREAD FOG THROUGHOUT MOST OF SOUTHERN
MAINLAND ALASKA TODAY. THIS WILL LIKELY REMAIN THE CASE THROUGH THE
NIGHT AS WELL. BIGGEST IMPACT FOR WEATHER IN THE SOUTH CENTRAL AREA
WILL BE GUSTY OUTFLOW WINDS ALONG THE NORTHERN GULF COAST. WHITTIER
WILL CONTINUE TO GUST TO 50 MPH OR MORE AND THE VALDEZ AREA IS ALSO
SUSCEPTIBLE TO STRONG WINDS AND SOME BLOWING SNOW...PARTICULARLY
THROUGH THOMPSON PASS.
SOUTHWEST ALASKA WILL CONTINUE TO SEE COLD TEMPERATURES AND LOW WIND
CHILLS TO 35 BELOW ZERO. AN UPPER LEVEL WAVE WILL BRING SOME CLOUDS
INTO THE AREA OVERNIGHT AND INTO TOMORROW BEFORE CLEARING OUT AGAIN.

.LONG TERM FORECAST...COLD AIR STILL ON TRACK TO MOVE INTO
SOUTH CENTRAL LATE TUESDAY AFTERNOON. GUSTY NORTHERLY WINDS THROUGH
CHANNELED AREAS WILL DEVELOP DURING THIS TIME AND PERSIST THROUGH THE
END OF THE WEEK. EXPECT COLD AND SUNNY CONDITIONS TO CONTINUE THROUGH
NEXT WEEKEND FOR MOST OF THE MAINLAND. OVER THE BERING SEA AND
ALEUTIANS...ABOVE NORMAL TEMPERATURES AND RELATIVELY CALM WEATHER
WILL CONTINUE.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 121 129 130 132 150 155 160 165 180.
         HEAVY FREEZING SPRAY 160 180.
FIRE WEATHER...NONE.

DEC 10