Gale Warning 317, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AKDT MON MAR 23 2009

.DISCUSSION...
REDOUBT VOLCANO AT LONG LAST HAS FINALLY ERUPTED. A PLUME OF ASH IS
MOVING NORTH AND WILL STAY WEST OF ANCHORAGE AND PALMER. SOME ASH
WAS REPORTED IN SKWENTNA EARLY THIS MORNING...AND ASHFALL AMOUNTS
ARE EXPECTED TO BE VERY LIGHT AND CONFINED TO GENERALLY WEST OF A
LINE FROM WILLOW AND TALKEETNA.

THE WEATHER PICTURE IS DOMINATED BY A BLOCKING RIDGE OVER EASTERN
SIBERIA. THE DOWNSTREAM TROUGH IS CENTERED OVER BRISTOL BAY WITH
CYCLONIC FLOW OVER THE EASTERN BERING SEA AND SOUTHERN ALASKA. THE
BLOCK AND ASSOCIATED DOWNSTREAM LOW WILL SLOWLY RETROGRADE THROUGH
THE WEEK AND INTO THE WEEKEND WITH SOUTHERN ALASKA REMAINING IN
CYCLONIC FLOW ON THE WARM SIDE OF THE TROUGH.

A CYCLONE SPINNING UP IN THE GULF OF ALASKA ON THE EAST SIDE OF THE
BRISTOL BAY LOW WILL MOVE NORTH TODAY. THIS LOW WILL BE JUST EAST OF
KODIAK THIS AFTERNOON. MOST OF THE WINDS AND PRECIPITATION WITH THIS
LOW WILL BE NEAR THE GULF COAST WITH LOCAL PENETRATIONS INLAND. THE
LOW WILL WEAKEN AND MOVE EAST TONIGHT INTO TUESDAY AS ANOTHER SYSTEM
SOUTH OF THE ALEUTIANS COMES RACING IN FROM THE WEST AND KICKS IT
OUT.

THE WARM FRONT FROM THE NEXT SYSTEM WILL REACH THE ALASKA PENINSULA
TUESDAY NIGHT AND AFFECT MOST OF SOUTHERN ALASKA BY WEDNESDAY WHEN
THE LOW CENTER WILL BE JUST SOUTHWEST OF KODIAK ISLAND.

A CONTINUING SERIES OF IMPULSES AROUND THE MEAN LOW POSITION WILL
AFFECT SOUTHERN ALASKA FOR THE REMAINDER OF THE WEEK AND INTO THE
WEEKEND.

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

LUDWIG MAR 09