Small Craft Advisory 217, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTH CENTRAL AND SOUTHWEST ALASKA
200 PM ADT TUE MAR 11 2008

.MODEL DISCUSSION...
THE MODELS REMAIN IN RELATIVELY GOOD AGREEMENT WITH ANY DIFFERENCES
IN THE SMALL SCALE DETAILS. THE PRIMARY CONCERN IS THE TROUGH FROM
THE SOUTHERN YUKON TERRITORY TO THE KENAI PENINSULA AND THE WEAK LOW
IN THE WEST END OF THIS TROUGH. AT THE UPPER LEVELS THE MODELS ARE IN
GOOD AGREEMENT.

.ANALYSIS AND UPPER LEVELS...
A WEAK UPPER TROUGH OVER SOUTH CENTRAL ALASKA IS SUPPORTING THE WEAK
SURFACE LOW PRESSURE. A SURFACE AND UPPER LEVEL RIDGE LIES ACROSS THE
GULF OF ALASKA TO THE SOUTHWEST END OF KODIAK ISLAND. A LARGE SURFACE
AND UPPER LEVEL LOW IS ABOUT 600 MILES SOUTH OF THE ALASKA PENINSULA
AND AN INTENSIFYING LOW IS ABOUT 900 MILES SOUTH OF SHEMYA SUPPORTED
BY AN UPPER LEVEL TROUGH.

.SHORT TERM FORECAST...
NO SIGNIFICANT CHANGES ARE ANTICIPATED FROM THIS MORNINGS FORECAST
PACKAGE. WE STILL EXPECT THE SURFACE AND UPPER LEVEL LOW OVER THE
SOUTH CENTRAL REGION TO KEEP THE POSSIBILITY OF SNOW SHOWERS OVER THE
REGION THROUGH WEDNESDAY.

OUT WEST THE INTENSIFYING STORM MOVING TOWARD THE WESTERN AND CENTRAL
ALEUTIANS IS STILL ON TRACK TO IMPACT THE REGION BY WEDNESDAY MORNING
AS GALE FORCE WINDS MOVE INTO THE ADAK AREA.

OVER THE BERING SEA A WIDE SPREAD LAYER OF LOW CLOUDS IS IN PLACE
UNDER THE RIDGE. THE NORTHWEST AND WEST ONSHORE FLOW ALONG THE BERING
COAST IS KEEPING THE DELTA AND BRISTOL BAY AREAS IN THE CLOUDS AND
PERIODS OF LIGHT SNOW. THESE CONDITIONS SHOULD PERSIST THROUGH
WEDNESDAY AND THURSDAY UNTIL THE STRONG EAST FLOW ASSOCIATED WITH THE
INTENSE BERING STORM MIXES OUT THE LOWER LAYER THURSDAY NIGHT.

.LONG TERM FORECAST...
THE UPPER TROUGH AND ASSOCIATED SURFACE LOW OVER THE SOUTH CENTRAL
REGION SHOULD MOVE OFF TO THE EAST AS THE STRONG UPPER RIDGE BUILDS
INTO SOUTHWEST ALASKA WEDNESDAY NIGHT AND THURSDAY. THE SURFACE LOW
NEAR VANCOUVER ISLAND WILL HAVE A TROUGH EXTENDING TO THE PRINCE
WILLIAM SOUND AREA THROUGH THURSDAY. THIS TROUGH WILL INTENSIFY ALONG
THE NORTH GULF COAST THURSDAY NIGHT AND ANTICIPATE POTENTIAL STRONG
GAP WIND THROUGH THE CHUGACH MOUNTAINS WITH THE INCREASED PRESSURE
GRADIENT AND COLDER AIR OVER THE EASTERN INTERIOR.

THE FIRST STORM MOVING TO THE ALEUTIANS WEDNESDAY WILL BE ABSORBED
INTO ANOTHER MASSIVE INTENSE STORM MOVING TO JUST SOUTH OF THE
CENTRAL ALEUTIANS THURSDAY NIGHT. OF CONCERN WITH THIS STORM IS THE
STRONG EAST WIND AND POTENTIAL FOR SNOW IN THE PRIBILOF ISLANDS THAT
MAY RESULT IN A BLIZZARD THURSDAY NIGHT AND FRIDAY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 172 175 176 413.
FIRE WEATHER...NONE.

SAM MAR 08