Gale Warning 129, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 PM AKST FRI FEB 20 2009

.MODEL DISCUSSION...
MODELS ARE IN VERY GOOD AGREEMENT THROUGH SUNDAY NIGHT AND ARE
CONSISTENT WITH PREVIOUS RUNS. WINDS IN THE FIRST 12 HOURS OF THE GFS
HAVE MATCH OBSERVED WINDS OVER THE CENTRAL ALEUTIANS BETTER THAN THE
NAM MODEL, WHICH APPEAR TO BE A LITTLE TOO WEAK. I WOULD SUGGEST
GOING WITH THE GFS OVER THE BERING SEA FOR TONIGHT, OTHERWISE, IT
YOUR CHOICE.

.ANALYSIS AND UPPER LEVELS...
THE UPPER TROUGH MOVING THROUGH SOUTHCENTRAL ALASKA WILL HAVE LITTLE
AFFECT DUE TO THE DRYNESS OF THE ATMOSPHERE BEHIND THE FRONT. THE
UPPER RIDGE OVER THE EASTERN BERING SEA CONTINUES TO BUILD.

AT THE SURFACE...THE COLD FRONT MOVING THROUGH THE COPPER RIVER BASIN
WILL MOVE INTO THE YUKON TONIGHT. NORTH WINDS WILL INCREASE OVER
SOUTHCENTRAL THROUGH THIS EVENING AND WILL BE ESPECIALLY STRONG
THROUGH MOUNTAIN GAPS ALONG THE CENTRAL GULF COAST. AN INTENSE STORM
MOVING THROUGH THE WESTERN ALEUTIANS HAS PRODUCED WIND GUSTS IN
EXCESS OF 80 MPH THROUGH THE CENTRAL ALEUTIANS.

.SHORT TERM FORECAST...
UPPER AIR...THE UPPER TROUGH OVER THE COPPER RIVER BASIN WILL MOVE
INTO THE YUKON TERRITORY SATURDAY. THE UPPER RIDGE OVER THE EASTERN
BERING SEA WILL BECOME NEARLY STATIONARY OVER MAINLAND ALASKA
SATURDAY AND WILL SIGNIFICANTLY WEAKEN ANY FRONT APPROACHING THE WEST
COAST OF ALASKA THROUGH THE WEEKEND.

AT THE SURFACE...
SOUTHCENTRAL ALASKA AND THE GULF...A FEW SNOW SHOWERS OVER THE
INTERIOR WILL PERSIST THROUGH TONIGHT WITH THE PASSAGE OF THE UPPER
TROUGH. OTHERWISE, THE SKIES WILL GENERALLY CLEAR FROM THE WEST
THROUGH TONIGHT AND WILL REMAIN MOSTLY SUNNY THROUGH THE WEEKEND.
SOME MID TO HIGH LEVEL CLOUDS WILL MOVE INTO THE SUSITNA VALLEY AS A
WEAK UPPER SHORT WAVE TROUGH RIPPLES THROUGH THE RIDGE.

SOUTHWEST ALASKA...THE WEATHER FRONT ASSOCIATED WITH THE STORM OVER
THE WESTERN ALEUTIANS WILL MOVE EAST INTO THE KUSKOKWIM DELTA COAST
SATURDAY AFTERNOON THEN WILL DISSIPATE OVER THE SOUTHWEST INTERIOR
SATURDAY NIGHT. THE AREA OF STRONG WINDS AHEAD OF THE FRONT WILL
PRODUCE AREAS OF BLOWING SNOW ALONG THE COAST SATURDAY MORNING WHICH
WILL CONTINUE THROUGH SATURDAY EVENING. SNOW WILL MOVE INTO THE
KUSKOKWIM DELTA BY SATURDAY AFTERNOON AND WILL SPREAD INTO WESTERN
BRISTOL BAY AND WESTERN KUSKOKWIM VALLEY SATURDAY NIGHT BEFORE
CHANGING TO SNOW SHOWERS SUNDAY.

BERING SEA...THE STRONG STORM OVER THE WESTERN ALEUTIANS WILL
CONTINUE TO MOVE NORTH AND WEAKEN THROUGH TONIGHT THEN MOVE INTO
SIBERIA SATURDAY. THE ASSOCIATED WEATHER FRONT OVER THE SOUTHWEST
BERING AND CENTRAL ALEUTIANS WILL MOVE NORTHEAST INTO WESTERN ALASKA
SATURDAY. THE AREA OF STORM TO HURRICANE FORCE WINDS AHEAD OF THE
FRONT WILL WEAKEN TO STORM FORCE WINDS AS IT MOVES THROUGH THE
PRIBILOFS LATE TONIGHT AND WILL CONTINUE TO WEAKEN TO GALES AS IT
APPROACHES THE WEST COAST. A SECOND STORM DEVELOPING WEST OF HOKKAIDO
WILL MOVE NORTHEAST INTO THE NORTHERN BERING SEA BY SUNDAY AFTERNOON.

STORM FORCE WILL WILL MOVE INTO THE WESTERN ALEUTIANS SATURDAY
AFTERNOON THEN WEAKEN TO GALES OVER THE CENTRAL ALEUTIANS SATURDAY
NIGHT.

.LONG TERM FORECAST...
THE UPPER RIDGE OVER MAINLAND ALASKA WILL BEGIN TO DRIFT EAST
SATURDAY NIGHT AND WILL MOVE INTO THE YUKON TERRITORY AND SOUTHEAST
ALASKA TUESDAY NIGHT. STORM COMING OFF THE NORTH PACIFIC WILL TRACK
THROUGH THE CENTRAL BERING MONDAY AND TUESDAY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WATCH FOR 151 SATURDAY.
MARINE...STORM...170, 172, 179
         GALE...120, 121, 129, 130, 132, 155, 165, 175, 176, 180
FIRE WEATHER...NONE.

NM FEB 09