Gale Warning 229, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AKST THU MAR 4 2010

.MODEL DISCUSSION...
WESTERN PRINCE WILLIAM SOUND LOW NOT RECOGNIZED WELL BY MODELS. TRACK
OF LOW WILL BE IMPORTANT AS IT MOVES INLAND TODAY TOWARDS THE
SOUTHERN SUSITNA VALLEY AND NONE OF THE MODELS ARE ABLE TO RESOLVE
THIS. MAV AND MET MOS UNRELIABLE FOR SOUTHCENTRAL TODAY...BUT MET MOS
THE BETTER OF THE TWO.
BIG LOW OUT WEST RECOGNIZED WELL BY ALL MODELS AND TRACKING TOWARDS
THE CENTRAL ALEUTIANS AS EXPECTED. SOME DISCREPANCY ON CENTRAL
PRESSURE BUT EXPECTED TO PRODUCE STORM AND HURRICANE FORCE WINDS
IRREGARDLESS. GFS PREFERRED OUT WEST FOR CONSISTENCY.

.ANALYSIS AND UPPER LEVELS...
UPPER LOW CENTER AT 500 MB POSITIONED OVER SOUTHWEST ALASKA WITH
TROUGH EXTENDING ACROSS THE GULF OF ALASKA...FEATURE WEAKENS AND
LIFTS NORTHWARD IN ADVANCE OF APPROACHING RIDGE OF HIGH PRESSURE
BUILDING IN FROM THE WEST.
TROUGHING OVER WESTERN BERING AND WESTERN ALEUTIANS ORGANIZES INTO A
CLOSED CENTER AT 500 MB THIS AFTERNOON OVER THE CENTRAL ALEUTIANS.
CENTER TRACKS ALONG THE CENTRAL ALEUTIANS AND INTO BRISTOL BAY REGION
BY FRI AFTERNOON.
UPPER LEVEL HIGH POSITIONED OVER RUSSIAN FAR EAST SINKS SOUTHWARD
BECOMING ANCHORED OVER CENTRAL BERING SEA BY LATE FRIDAY NIGHT.

.SURFACE FEATURES...
A 989 MB LOW IN WESTERN PRINCE WILLIAM SOUND WILL MOVE INLAND AND
DISSIPATE OVER THE SOUTHERN SUSITNA VALLEY THU AFTERNOON.
A 967 MB LOW JUST SOUTH OF ADAK WILL INTENSIFY TO 958 MB JUST SOUTH
OF SEGUAM ISLAND THU AFTERNOON. THE LOW AT THIS STAGE HAS EXCELLENT
UPPER LEVEL SUPPORT AND IS ABLE TO MOVE TO SOUTHERN SHELIKOF STRAIT
BY FRI MORNING WITH LITTLE CHANGE IN CENTRAL PRESSURE. AFTERWORDS IT
MOVES INLAND AND WEAKENS TO 977 MB OVER THE SOUTHERN KUSKOKWIM VALLEY
FRI NIGHT.

.SHORT TERM FORECAST...
AS LOW POSITIONED OVER WESTERN PRINCE WILLIAM SOUND MOVES INLAND...
COLD AIR IS PULLED SOUTHWARD ACROSS THE KENAI PENINSULA AND WESTERN
PRINCE WILLIAM SOUND. GOOD SNOW PATTERN TODAY FOR THE WESTERN KENAI
PENINSULA. GUSTY SOUTHEAST WINDS HAVE REDEVELOPED THROUGH CHANNELED
AREAS AND ONCE AGAIN DOWNSLOPING WILL LIMIT SNOW AMOUNTS IN THE
ANCHORAGE AND MATANUSKA ZONES.
GRADIENT TIGHTENS ALONG GULF COAST THROUGH TOMORROW AFTERNOON. 75 MPH
PLUS WINDS POSSIBLE THROUGH PORTAGE VALLEY AND ALONG TURNAGAIN ARM
TOMORROW AND TOMORROW EVENING.
BLIZZARD WARNING FOR CENTRAL ALEUTIANS ALREADY BEGINNING TO VERIFY.
PLENTY OF SNOW AND HURRICANE FORCE WINDS ALONG THE NORTHERN EDGE OF
THE APPROACHING NORTH PACIFIC LOW.
MORE BLIZZARD WARNINGS TO COME. AS SYSTEM PUSHES NORTH AND EAST
EXPECT LOW VISIBILITIES IN SNOW AND BLOWING SNOW TO DEVELOP OVER THE
PRIBILOF ISLANDS THIS AFTERNOON...THE EASTERN ALEUTIANS AND BRISTOL
BAY THIS EVENING...AND THE ALASKA PENINSULA AND KUSKOKWIM VALLEY LATE
TONIGHT.
SIGNIFICANT WARMING TO THE EAST OF THE LOW CENTER. PRECIPITATION OVER
THE EASTERN ALEUTIANS AND ALASKA PENINSULA WILL BEGIN AS A MIX OF
SNOW AND RAIN THEN CHANGE OVER TO SNOW SHOWERS POST FRONTAL PASSAGE.

.LONG TERM FORECAST...
BIG STORM GRADUALLY WEAKENS AND DIES AFTER MOVING INTO CENTRAL
INTERIOR ALASKA. A SERIES OF SMALLER LOWS MIGRATES ALONG THE ALEUTIAN
CHAIN BETWEEN 60 AND 120 HOURS. NEXT MONSTER ALEUTIAN LOW NOT
EXPECTED UNTIL AT LEAST DAY 8.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...HIGH WIND 101 125
         BLIZZARD WATCH 155 181
         BLIZZARD WARNING 161 185 187 195
MARINE...GALE 121 129 138 140 141 176 179 180 411 412
         STORM 120 125 130 132 150 155 160 165 170 171 175 351 352
               413 414
         HURRICANE FORCE 172
         HEAVY FREEZING SPRAY 155 165 170 171 172 176 179
FIRE WEATHER...NONE.

ASB MAR 10