Small Craft Advisory 288, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
300 PM AKDT TUE MAR 31 2009

.ANALYSIS AND UPPER LEVELS...
A 995 MB LOW SOUTH OF KODIAK ISLAND WILL MOVE ACROSS THE SOUTHERN
GULF THROUGH WEDNESDAY. ANOTHER 994 MB LOW EVIDENT ON SATELLITE
IMAGERY IS NORTHEAST OF SHEMYA...MOVING TO THE NORTHEAST. PROGRESSIVE
HIGH PRESSURE IS SANDWICHED BETWEEN THESE TWO LOWS. IN THE UPPER
LEVELS...A BROAD TROUGH CENTERED OVER THE WESTERN BERING SEA IS
SLOWLY LIFTING NORTHEASTWARD...ALLOWING FLOW TO BECOME INCREASINGLY
ZONAL ACROSS THE AREA OF RESPONSIBILITY.

.MODEL DISCUSSION...
THE GFS IS THE PREFERRED MODEL SOLUTION FOR THE AFTERNOON PACKAGE DUE
TO GOOD CONSISTENCY AND INITIALIZATION. MODELS ARE HAVING PROBLEMS
RESOLVING THE POSITION AND INTENSITY OF INDIVIDUAL LOW CENTERS MOVING
FROM THE NORTH PACIFIC INTO THE GULF OF ALASKA. OVERALL CONSENSUS ON
THE LARGE SCALE PATTERN IS SATISFACTORY THROUGH 12Z FRIDAY.

.SHORT TERM FORECAST...
.SOUTHCENTRAL...
FAIR WEATHER WILL BE SETTING UP ACROSS MOST OF SOUTHCENTRAL OVER THE
NEXT COUPLE OF DAYS AS TRANSITORY RIDGING MOVES THROUGH THE REGION.
THE CHANCE FOR SNOW SHOWERS WILL REMAIN ON WEDNESDAY IN RESPONSE TO
SHORTWAVE IMPULSES PUSHING ACROSS THE AREA...BUT MANY AREAS WILL
REMAIN DRY. THE SUSITNA VALLEY AND COPPER RIVER BASIN WILL SEE THE
MOST WIDESPREAD SNOW...ALBEIT STILL SCATTERED IN NATURE. RAIN AND
SNOW WILL BE MOVING INTO KODIAK THURSDAY AS THE LOW SOUTH OF THE
ALEUTIANS MOVES INTO THE GULF.

.SOUTHWEST...
GENERALLY BENIGN WEATHER ACROSS THE REGION IN THE SHORT TERM. THE
BERING SEA LOW WILL SPREAD SNOW SHOWERS ACROSS THE KUSKOKWIM DELTA
AND WESTERN CAPES OF BRISTOL BAY ON WEDNESDAY. THE NEXT NORTH PACIFIC
LOW MOVING INTO THE GULF WILL SPREAD PRECIPITATION ACROSS THE AKPEN
AND BRISTOL BAY ON THURSDAY. WARM AIR ASSOCIATED WITH THIS SYSTEM
WILL LEAD TO A RAIN SNOW MIX ACROSS THE AKPEN...REMAINING SNOW FOR
BRISTOL BAY.

.BERING SEA AND ALEUTIANS...
SCATTERED SNOW SHOWERS WILL PERSIST OVER THE WESTERN ALEUTIANS
THROUGH THURSDAY. WIDESPREAD SNOW WILL OCCUR OVER THE PRIBILOFS
TONIGHT INTO TOMORROW MORNING AS THE LOW IN THE BERING MOVES
NORTHEAST. AN APPROACHING NORTH PACIFIC LOW WILL SPREAD RAIN AND SNOW
ACROSS THE CENTRAL AND EASTERN ISLANDS WEDNESDAY AND THURSDAY. AS
THIS LOW MOVES INTO THE GULF...COLD AIR ADVECTION WILL TURN
PRECIPITATION BACK TO ALL SNOW.

.LONG TERM FORECAST...
PROGRESSIVE FLOW LOOKS TO REMAIN ZONAL ACROSS SOUTHCENTRAL AND
SOUTHWEST ALASKA THROUGH THE EXTENDED. THEREFORE EXPECT PERIODS OF
UNSETTLED WEATHER AS LOWS MOVE FROM THE NORTH PACIFIC ACROSS THE
ALEUTIAN CHAIN...EVENTUALLY IMPACTING THE MAINLAND.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...GALE...132 170 172 175
FIRE WEATHER...NONE

NRH MAR 09

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ANCHORAGE AK
135 AM AKDT WED APR 1 2009

AKZ145-012000-

...TRACE AMOUNTS OF ASHFALL OVER THE NORTHEAST PORTIONS OF PRINCE
WILLIAM SOUND IN THE VICINITY OF VALDEZ AND THE SOUTHERN PORTIONS OF
THE COPPER RIVER BASIN ALONG THE CHUGACH MOUNTAINS...

THERE ARE TRACE AMOUNTS OF ASH FROM THE REDOUBT ERUPTION TUESDAY
AFTERNOON NOW FALLING IN THE VICINITY OF VALDEZ AND MAY FALL THROUGH
PORTIONS OF THE SOUTHERN COPPER RIVER BASIN ALONG THE CHUGACH
MOUNTAINS THROUGH EARLY THIS MORNING.

AVOID EXCESSIVE EXPOSURE TO ASH...ESPECIALLY THOSE WITH RESPIRATORY
SENSITIVITIES. PROTECT CRITICAL ELECTRONICS AND OTHER EQUIPMENT FROM
CONTAMINATION.

THIS STATEMENT WILL ONLY BE UPDATED IF CONDITIONS CHANGE.

SPECIAL WEATHER STATEMENT...RETRANSMISSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
135 AM AKDT WED APR 1 2009

AKZ131-141-011330-

...TRACE AMOUNTS OF ASHFALL OVER THE NORTHEAST PORTIONS OF PRINCE
WILLIAM SOUND IN THE VICINITY OF VALDEZ AND THE SOUTHERN PORTIONS OF
THE COPPER RIVER BASIN ALONG THE CHUGACH MOUNTAINS...

THERE ARE TRACE AMOUNTS OF ASH FROM THE REDOUBT ERUPTION TUESDAY
AFTERNOON NOW FALLING IN THE VICINITY OF VALDEZ AND MAY FALL THROUGH
PORTIONS OF THE SOUTHERN COPPER RIVER BASIN ALONG THE CHUGACH
MOUNTAINS THROUGH EARLY THIS MORNING.

AVOID EXCESSIVE EXPOSURE TO ASH...ESPECIALLY THOSE WITH RESPIRATORY
SENSITIVITIES. PROTECT CRITICAL ELECTRONICS AND OTHER EQUIPMENT FROM
CONTAMINATION.

THIS STATEMENT WILL ONLY BE UPDATED IF CONDITIONS CHANGE.