Gale Warning 279, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 PM AKDT MON MAR 22 2010

.ANALYSIS AND UPPER LEVELS...
UPPER LEVEL...AN INTENSE UPPER LOW OVER NORTHERN CANADA HAS EXTENDED
A TROUGH INTO THE TANANA VALLEY. A WEAK UPPER LOW SOUTH OF KODIAK
ISLAND REMAIN NEARLY STATIONARY. AN UPPER RIDGE OVER THE CENTRAL
ALEUTIANS AND CENTRAL BERING SEA IS BEING PUSHED EASTWARD BY A STRONG
LOW OVER THE KAMCHATKA PENINSULA.

AT THE SURFACE...THERE IS A STRONG HIGH OVER THE BEAUFORT SEA WHICH
HAS KEPT MOST OF MAINLAND ALASKA NEARLY CLOUD-FREE FOR THE LAST FEW
DAYS. DEVELOPING LOW PRESSURE OVER THE GULF OF ALASKA HAS MOVED
CLOUDS AND ISOLATED SNOW SHOWERS INTO THE CENTRAL GULF COAST, KENAI
PENINSULA AND THE ANCHORAGE BOWL. A WEATHER FRONT OVER THE WESTERN
ALEUTIANS CONTINUES TO MOVE EAST.

.MODEL DISCUSSION...
MODELS ARE IN FAIRLY GOOD AGREEMENT OVER MAINLAND ALASKA AND THE
BERING SEA, BUT HAVE A FEW DIFFERENCES OVER THE GULF. THE GFS AND NAM
MODELS DEVELOP DOUBLE-CENTERED LOW OVER THE GULF TONIGHT AND TUESDAY
WHILE THE EC AND UKMET MODEL KEEP IT AS A SINGLE-CENTERED LOW.
CURRENT SATELLITE IMAGES SHOW MULTIPLE WAVES ALONG THE FRONT, ANY OF
WHICH COULD DEVELOP INTO THE SECOND LOW CENTER. THEREFORE, THE
DOUBLE-CENTERED LOW SEEM TO BE THE MOST LIKELY SCENARIO.

.SHORT TERM FORECAST...
SOUTH-CENTRAL AK AND THE GULF...A DEVELOPING COMPLEX LOW SOUTH OF THE
GULF OF ALASKA WILL MOVE INTO THE GULF TONIGHT AND TUESDAY THEN TURN
WEST AND WEAKEN OVER KODIAK ISLAND WEDNESDAY. THE ASSOCIATED FRONT
WILL MOVE THROUGH THE GULF THROUGH TUESDAY AND MOVE ONSHORE ALONG THE
CENTRAL GULF COAST TUESDAY NIGHT. RAIN, SNOW AND GUSTY EAST WINDS
WILL MOVE INTO KODIAK ISLAND TONIGHYT AND SPREAD INTO PRINCE WILLIAM
SOUND AND THE SOUTHERN KENAI PENINSULA TUESDAY AFTERNOON. WINDS WILL
DIMINISH AND PRECIPITATION WILL BECOME SHOWERS AS THE FRONT MOVES
INLAND AND WEAKENS TUESDAY NIGHT.

SOUTHWEST MAINLAND...EASTERLY FLOW ACROSS MAINLAND ALASKA WILL
CONTINUE TO FEED COLD DRY AIR INTO SOUTHWEST INTERIOR AND KEEP THE
SKIES MOSTLY CLEAR. SOME CLOUDS AND ISOLATED SHOWERS OVER THE
SOUTH-CENTRAL COAST WILL ALSO BE CAUGHT UP IN THE EASTERLY FLOW AND
MOVE INTO BRISTOL BAY TUESDAY AND TUESDAY NIGHT.

THE BERING SEA AND ALEUTIANS...THE WEATHER FRONT OVER THE WESTERN
ALEUTIANS AND SOUTHWEST BERING WILL WEAKEN AS IT STRETCHES EASTWARD
ACROSS THE SOUTHERN BERING SEA AND THE REST OF THE ALEUTIAN CHAIN
THROUGH TUESDAY NIGHT. GALE FORCE WINDS AHEAD OF THE FRONT WILL
DIMINISH TONIGHT AND TUESDAY. RAIN AND SNOW AHEAD OF THE FRONT WILL
BECOME SHOWERS BEHIND IT.

.LONG TERM FORECAST...
A NUMBER OF LOW PRESSURE SYSTEMS WILL MOVE INTO THE GULF OVER THE
LATTER HALF OF THE WEEK. THIS WILL BRING MORE RAIN, SNOW AND GUSTY
WINDS THE CENTRAL GULF COAST AND KODIAK ISLAND AND WILL SPREAD MORE
CLOUDS AND A FEW SHOWERS INTO THE REST OF SOUTHERN ALASKA.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 120 130 170 172 175
FIRE WEATHER...NONE.

NM MAR 10