Gale Warning 1077, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 AM AKST WED DEC 22 2010

.MODEL DISCUSSION...
MODELS IN VERY GOOD AGREEMENT THROUGH 120 HOURS. NAM PREFERRED IN
THE SHORT TERM DUE TO SUPERIOR HANDLING OF PRESSURE GRADIENT ALONG
GULF COAST AND EASTERN BERING SEA. TRENDED MID AND LONG RANGE
FORECAST TOWARDS THE TUE HPC SOLUTION.

.UPPER LEVELS...
UPPER LEVEL RIDGE OF HIGH PRESSURE OVER THE NORTH PACIFIC AND
WESTERN BERING HOLDS THROUGH THE REMAINDER OF THE WEEK. A WELL
ORGANIZED UPPER LOW CENTER JUST SOUTH OF THE GULF OF ALASKA
GRADUALLY WEAKENS THROUGH THURSDAY NIGHT THEN BEGINS TO GRADUALLY
MIGRATE NORTHWESTWARD IN RESPONSE TO RIDGE DEVELOPMENT OVER WESTERN
CANADA.

.SURFACE ANALYSIS AND SHORT TERM FORECAST...
A 987 MB LOW IN THE CENTRAL GULF OF ALASKA GRADUALLY WEAKENS AND
DRIFTS SOUTHWARD THROUGH THURSDAY NIGHT. A HIGH AMPLITUDE TROUGH OF
LOW PRESSURE DEVELOPS ALONG THE NORTH GULF COAST WED MORNING AND
PERSISTS THROUGH THURSDAY.
TIGHT PRESSURE GRADIENT ALONG GULF COAST AND OVER THE EASTERN BERING
SEA GRADUALLY SLACKENS FROM THE WEST AS THE GULF LOW DROPS
SOUTHWARD. NORTHERLY GAP WINDS GUSTING 50 TO 100 MPH THROUGH
CHANNELED AREAS OF THE EASTERN ALEUTIANS AND ALASKA PENINSULA SHOULD
TAPER OFF BY EARLY THIS EVENING. GUSTY NORTH WINDS 30 TO 45 MPH WILL
PERSIST ACROSS KODIAK ISLAND THROUGH TONIGHT.   NORTHERLY GAP WINDS
OF 25 TO 50 MPH THROUGH CHANNELED AREAS OF THE CHUGACH RANGE AND
ACROSS EXPECTED TO LINGER THROUGH THURSDAY.
HIGH PRESSURE PERSISTS OVER THE CENTRAL BERING THROUGH THURSDAY BUT
A STRONG NORTH PACIFIC LOW MOVES UP FROM THE SOUTH TO JUST SOUTH OF
SHEMYA THURSDAY NIGHT WILL SPREAD RAIN SNOW AND EASTERLY GALES
ACROSS THE WESTERN ALEUTIANS THURSDAY NIGHT.

.LONG TERM FORECAST...
LOW PRESSURE PERSISTS SOUTH OF THE GULF OF ALASKA. HIGH PRESSURE
OVER THE BERING GIVES WAY TO A RAPIDLY ADVANCING OCCLUDED FRONT
BEGINNING FRIDAY. EXPECT INCREASINGLY COLD AND DRY AND PERIODICALLY
WINDY CONDITIONS TO PREVAIL ACROSS SOUTHWESTERN AND SOUTHCENTRAL
ALASKA FOR THE WEEKEND. EXPECT A RETURN TO WARM WET AND WINDY FOR
THE ALEUTIANS AND BERING SEA.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...HIGH WIND 181
MARINE...GALE 121 129 130 132 138 160 165 171 180 185
         STORM 150 155 170
         HEAVY SPRAY 121 129 130 138 140 141 150 160 165 180
FIRE WEATHER...NONE.

ASB DEC 10