Gale Warning 144, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
300 PM AKST SUN FEB 1 2009

.MODEL DISCUSSION...MODELS ARE DOING WELL IN THE NEAR TERM...AND ARE
QUITE REASONABLE IN THE LONGER TERM. IN THE EAST THE NAM IS THE
PREFERRED MODEL FOR THE LOW ALONG THE NORTH GULF COAST AND DOES WELL
THROUGH TUESDAY. AFTER THAT THE ECMWF AND GFS LOOK BETTER WITH THE
DEVELOPMENT OF A TRIPLE POINT LOW NEAR KODIAK DEVELOPING TUESDAY. OF
THOSE TWO THE ECMWF IS PREFERRED AS ANOTHER TRIPLE POINT DEVELOPS TO
THE SOUTH AND MOVES EASTWARD.
IN THE WEST THE MODELS LOOK VERY GOOD THROUGH TUESDAY. BEYOND THAT
THE GFS AND ECMWF ARE STRUGGLING TO FIND THE EXACT LOCATION OF THE
LOW IN THE WESTERN BERING SEA. GIVEN THE DYNAMICS OF THE SYSTEM THEY
ARE NOT DOING BAD AT ALL WITH THE DIFFERENCES HAVING ONLY MINIMAL
IMPACT ON THE FORECASTS AT THIS TIME.

.ANALYSIS AND UPPER LEVELS...A DEEP UPPER LEVEL TROUGH EXTENDS FROM
THE ARCTIC COAST SOUTHWARD TO KODIAK ISLAND AND THEN CONTINUES TO
AROUND 30N. THIS TROUGH WILL MOVE EASTWARD OVER THE NEXT DAY AND BE
OVER THE CENTRAL GULF BY MONDAY AFTERNOON. THE 250 MB JET STREAM IS
AMPLIFIED AROUND THIS TROUGH AND IS BETWEEN 140 AND 160 KT AS IT
CROSSES THE CENTRAL ALEUTIANS AND THEN HEADS SOUTHEAST. THIS JET IS
ALSO HELPING TO DEEPEN A STRONG LOW THAT WILL BE MOVING INTO THE
WESTERN BERING SEA BY MONDAY NIGHT. THE JET WILL THEN FLATTEN OUT AND
BECOME MORE ZONAL SOUTH OF THE AREA BY TUESDAY.

THERE ARE TWO SURFACE FEATURES THAT ARE SIGNIFICANT TODAY. THE FIRST
IS AN OLD LOW THAT IS SITUATED JUST SOUTH OF CORDOVA. THIS LOW IS
BEING FED BY COLD AIR ADVECTION OUT OF THE BARREN ISLANDS AND IS A
BIT STRONGER AND FARTHER WEST THAN EXPECTED. IT HAS BROUGHT SNOW TO
CORDOVA AND VALDEZ TODAY AS WELL AS GLENNALLEN.

THE SECOND IS A STRONG AND STILL INTENSIFYING LOW SOUTHWEST OF THE
BERING SEA. THIS LOW WILL BECOME THE DOMINANT WEATHER FEATURE FOR THE
WESTERN AREAS THROUGH MOST OF THE WEEK. THIS LOW IS CURRENTLY
ANALYZED AT 950 MB AND IS EXPECTED TO DROP TO AT LEAST 945 MB BY
MONDAY AFTERNOON.

.SHORT TERM FORECAST...SNOW IN THE EASTERN PRINCE WILLIAM SOUND AND
COPPER RIVER AREAS WILL DIMINISH THIS EVENING AS THE LOW MOVES TO THE
EAST. THE STRONG WINDS THROUGH THE KACHEMAK GAP WILL INCREASE TONIGHT
AND BRING STORM FORCE WINDS AND HEAVY FREEZING SPRAY TO THAT AREA. A
SIGNIFICANT PORTION OF THE MARINE AREA WILL SEE HEAVY FREEZING SPRAY
OVERNIGHT THROUGH MONDAY NIGHT WITH THE COLD TEMPERATURES AND STRONG
WINDS. SOUTH CENTRAL ALASKA SHOULD SEE MOSTLY CLEAR SKIES TONIGHT
WITH MINIMAL FOG DEVELOPMENT IN THE COOK INLET REGION.

WINDS IN THE WESTERN BERING SEA AND ALEUTIAN ISLANDS WILL INCREASE TO
STORM FORCE OVERNIGHT AND THOSE WINDS WILL THEN START TO SLIGHTLY
WEAKEN AS THE FRONT MOVES EASTWARD THE NEXT FEW DAYS.

.LONG TERM FORECAST...THE FRONT IN THE WESTERN ALEUTIANS/BERING SEA
WILL BRING STORM FORCE WINDS TO THE WESTERN AND CENTRAL ALEUTIANS
BEFORE WEAKENING TO GALES. HUGE SWELLS WILL MOVE IN WITH THIS
SYSTEM...WITH SEAS LIKELY TO TOP 40 FEET ESPECIALLY ON THE PACIFIC
SIDE OF THE ALEUTIAN CHAIN TUESDAY AND WEDNESDAY. THE TEMPERATURES
APPEAR TO WARM QUICKLY ENOUGH TO KEEP BLIZZARD CONCERNS AT BAY...WITH
THE NOTABLE EXCEPTION OF THE PRIBILOFS WHERE THE SITUATION WILL HAVE
TO BE WATCHED CLOSELY FOR MONDAY NIGHT.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 120 132 138 155 160 165 170 171 179 180 185.
         STORM 130 172 175 176.
         HEAVY FREEZING SPRAY 121 125 129 130 132 138 140 141 150 155
160 165 179.
FIRE WEATHER...NONE.

FEB 09