Gale Warning 105, NWS Anchorage, AK

AREA FORECAST DISCUSSION...UPDATE
SOUTHCENTRAL AND SOUTHWEST ALASKA
730 PM AKST THU JAN 29 2009

.EVENING UPDATE...
18Z AND 0Z MODEL RUNS INITIALIZED VERY POORLY ON THE LOW IN THE GULF.
THE NAM/ECMWF HAS A BETTER POSITION OF THE SURFACE LOW THAN THE
GFS...BUT NO MODEL HAS A GREAT HANDLE ON THIS FEATURE. AFTER
COMPARING UPPER AIR SOUNDINGS TO MODEL TEMPERATURES AT 850MB...COLD
AIR IS AHEAD OF SCHEDULE AS IT CROSSES THE EASTERN ALEUTIANS AND
ALASKA PENINSULA. THIS IS LIKELY A RESULT OF THE POOR POSITIONING OF
THE SURFACE LOW WHICH IS TOO CLOSE TO KODIAK ISLAND. THE COLD AIR IS
ADVECTING THROUGH THE PASSES...PROMPTING AN UPDATE TO THE AFTERNOON
FORECAST TO COVER THE STRONGER GUSTS.

SNOW OVER SOUTHCENTRAL CONTINUES TO BE AN ENIGMA. THE HEAVIEST
SHOWERS HAVE REMAINED AWAY FROM THE POPULATED AREAS SO FORECASTED
SNOW TOTALS HAVE NOT BEEN VERIFYING...YET. RADAR ECHOES ARE
INCREASING IN THE SOUTHERN COOK INLET AS COLD AIR BEGINS TO SPILL
ACROSS THE RANGE. EXPECT THIS TREND TO CONTINUE WITH SNOW DEVELOPING
FROM HOMER TO KENAI IN THE NEXT 3 HOURS...SPREADING NORTHWARD TO
ANCHORAGE LATE TONIGHT. UNTIL THEN...ISOLATED TO SCATTERED SNOW
SHOWERS WILL PREVAIL EXCEPT ALONG THE COASTAL AREAS WHERE NUMEROUS
MODERATE TO HEAVY SNOW SHOWERS WILL CONTINUE OVERNIGHT.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...STORM 130.
         GALE 120 132 138 140 150 155 165 170 172 175 176
         HEAVY FREEZING SPRAY 121 129 130 138 140 141 150 160 165 179
FIRE WEATHER...NONE.

AB

PREVIOUS FORECAST DISCUSSION...

.MODEL DISCUSSION...
THE MODELS ARE IN GOOD AGREEMENT OVER MAINLAND ALASKA AND THE BERING
SEA THROUGH SATURDAY. THE MAIN AREA OF CONTENTION IS STILL ALONG THE
ALEUTIANS. MOST MODELS, WITH THE EXCEPTION OF THE ECMWF, ARE IN GOOD
AGREEMENT THROUGH FRIDAY AFTERNOON, BUT RAPIDLY DIVERGE THROUGH
SATURDAY.

.ANALYSIS AND UPPER LEVELS...
UPPER AIR...THE UPPER RIDGE OVER THE EASTERN GULF AND SOUTHEAST
ALASKA CONTINUES TO MOVE EAST. THE UPPER TROUGH OVER NORTHERN ALASKA
HAS DEEPENED AND FORMED A CLOSED LOW OVER THE KOBUK VALLEY. A WEAK
UPPER LOW OVER KODIAK ISLAND SOUTHWEST OF KODIAK ISLAND CONTINUES TO
MOVE NORTHEAST.

AT THE SURFACE...A COMPLEX LOW OVER THE KENAI PENINSULA AND KODIAK
ISLAND CONTINUES TO WEAKEN. THE WEATHER FRONT HAS DISSIPATED OVER THE
SOUTHCENTRAL INTERIOR THIS MORNING. SNOW CONTINUED TO FALL OVER THE
SUSITNA VALLEY AND THE EASTERN BRISTOL BAY ZONE. THERE WERE SCATTERED
SNOW SHOWERS ELSEWHERE OVER SOUTHCENTRAL ALASKA. COLD ADVECTION ON
THE WEST SIDE OF THE LOW HAS MAINTAINED THE GUSTY NORTH TO NORTHWEST
WINDS OVER SOUTHWEST ALASKA AND THE ALASKA PENINSULA.

.SHORT TERM FORECAST...
UPPER AIR...THE UPPER RIDGE OVER THE GULF WILL MOVE INTO WESTERN
CANADA FRIDAY MORNING. THE UPPER LOW NEAR KODIAK WILL MOVE INTO
PRINCE WILLIAM SOUND TONIGHT THEN DISSIPATE NEAR CAPE YAKATAGA FRIDAY
MORNING. THE UPPER LOW/TROUGH OVER WESTERN ALASKA WILL EXTEND INTO
THE SOUTHWEST INTERIOR FRIDAY THEN TURN EAST AND MOVE THROUGH THE
KENAI PENINSULA AND NORTHERN FRIDAY NIGHT BEFORE DISSIPATING
SATURDAY.

THE THE SURFACE...THE COMPLEX LOW OVER COOK INLET AND KODIAK ISLAND
WILL CONSOLIDATE INTO A SINGLE CENTER OVER THE NORTHWESTERN GULF
TONIGHT THEN GRADUALLY WEAKEN THROUGH SATURDAY.  HIGH PRESSURE OVER
THE CENTRAL BERING SEA WILL BUILD A LITTLE MORE NIGHT AND PERSIST
THROUGH SATURDAY. THE COMPLEX LOW PRESSURE SYSTEM SOUTH OF THE
ALEUTIANS WILL EVENTUALLY DEVELOP INTO A SINGLE LOW SOUTH OF THE
EASTERN ALEUTIANS SATURDAY.

SOUTHCENTRAL ALASKA...THE COMBINATION OF UPPER LOW MOVING THROUGH
SOUTHCENTRAL ALASKA AND THE SURFACE LOW MOVING INTO THE NORTHERN GULF
WILL PRODUCE AREAS OF SNOW OVER THE REGION TONIGHT THEN SCATTERED
SNOW SHOWERS ON FRIDAY. HEAVIEST SNOW WILL REMAIN ALONG THE GULF
COAST AND PRINCE WILLIAM SOUND. THE SNOW SHOWERS WILL END FRIDAY
NIGHT OVER THE INTERIOR SECTION AS HIGH PRESSURE BUILDS OVER CENTRAL
ALASKA. STRONG WINDS WILL DEVELOP OVER THE COOK INLET AND AROUND
KODIAK ISLAND TONIGHT, ESPECIALLY THROUGH CHANNELED TERRAIN ALONG THE
ALEUTIAN RANGE AND THROUGH THE BARREN ISLANDS AND WILL PERSIST
THROUGH EARLY SATURDAY NIGHT.

SOUTHWEST ALASKA...AREAS OF SNOW MAIN ALONG THE ALASKA AND ALEUTIAN
RANGES WILL END TONIGHT. GUSTY NORTH TO NORTHWEST WINDS WILL DIMINISH
TONIGHT. COLDER TEMPERATURES WILL SETTING INTO THE SOUTHWEST INTERIOR
AS SKIES REMAIN MOSTLY CLEAR THROUGH SATURDAY.

BERING SEA...NORTH WINDS OVER THE EASTERN BERING WILL DIMINISH A
LITTLE TONIGHT OTHERWISE SNOW SHOWERS WILL CONTINUE TO BE GENERATED
AS COLD AIR OFF THE ICE BLOWS ACROSS THE OPEN WATER THE SOUTHEASTERN
BERING. A STATIONARY TROUGH OF LOW PRESSURE OVER THE WESTERN BERING
WILL CONTINUE TO PRODUCE AREAS OF SNOW.

.LONG TERM FORECAST...
THE LOW OVER THE NORTHERN GULF WILL DISSIPATE  SATURDAY NIGHT. THE
LOW SOUTH OF THE EASTERN ALEUTIANS WILL MOVE EAST AND WEAKEN. THE
ASSOCIATED WEATHER FRONT EXTENDING NORTHEAST OF THE LOW WILL MOVE
INTO THE SOUTHERN GULF SATURDAY NIGHT WHERE IT WILL DEVELOP A TRIPLE
POINT LOW. THIS LOW WILL THEN MOVE ONSHORE NEAR YAKUTAT LATE SUNDAY
AND INTO THE YUKON TERRITORY MONDAY. A LARGE STORM OVER THE NORTHWEST
PACIFIC WILL CONTINUE TO DEEPEN AS IT MOVES TOWARD THE WESTERN
ALEUTIANS MONDAY. GALE AND STORM FORCE WINDS WILL MOVE INTO THE
WESTERN ALEUTIANS SUNDAY THEN SPREAD INTO THE CENTRAL ALEUTIANS AND
WESTERN BERING SEA SUNDAY NIGHT AND INTO THE EASTERN BERING MONDAY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...STORM 130.
         GALE 132, 138, 140, 150, 155, 160, 172, 175
FIRE WEATHER...NONE.

NM JAN 09