Small Craft Advisory 329, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 PM AKDT TUE MAY 10 2011

.ANALYSIS AND UPPER LEVELS...
.UPPER LEVELS...AN UPPER LOW OVER THE SOUTHEASTERN GULF CONTINUES TO
MOVE SOUTH INTO THE NORTHEAST PACIFIC. A WEAK UPPER TROUGH HAS
DEVELOPED OVER NORTHWEST ALASKA OVERNIGHT AND HAS MOVE CLOUDS INTO
THE LOWER KUSKOKWIM VALLEY AND KUSKOKWIM DELTA. AN UPPER RIDGE OVER
THE CENTRAL ALEUTIANS AND CENTRAL BERING CONTINUES TO DRIFT EAST
TOWARD MAINLAND ALASKA. A STRONG 300 MB NORTHERLY JET ALONG THE
KUSKOKWIM DELTA COAST AND THE ALASKA PENINSULA HAS CREATED GUSTY
WINDS OVER SOUTHWEST ALASKA.
.AT THE SURFACE...AN AREA OF LOW PRESSURE OVER WESTERN CANADA AND THE
NORTHEAST PACIFIC COMBINED WITH A STRONG SURFACE RIDGE OVER THE
EASTERN BERING HAS PRODUCED A DRY NORTHERLY FLOW OVER THE SOUTHERN
MAINLAND. A STRONG STORM SYSTEM OVER THE NORTHWEST PACIFIC HAS
BROUGHT RAIN AND GALE FORCE WINDS TO THE WESTERN ALEUTIANS.

.MODEL DISCUSSION...
THE MODELS ARE IN VERY GOOD AGREEMENT THOUGH THE NAM IS PREFERRED
OVER SOUTHCENTRAL ALASKA BECAUSE OF THE FINER DETAIL ON THE WIND
FIELDS.

.SHORT TERM FORECAST...
BOTH UPPER AND SURFACE RIDGES OVER THE BERING WILL DRIFT INTO
NORTHERN AND WESTERN ALASKA BY THURSDAY. THE UPPER JET ALONG THE
BERING SEA COAST WILL MOVE INTO THE WESTERN INTERIOR WEDNESDAY AND
OVER THE SUSITNA VALLEY AND THE KENAI PENINSULA THURSDAY.

.SOUTHCENTRAL ALASKA...CLEAR DRY WEATHER WILL CONTINUE THROUGH
THURSDAY. NORTHERLY WINDS WILL GRADUALLY INCREASE THROUGH THURSDAY AS
THE UPPER JET MOVES OVER THE AREA. WINDS WILL BE ESPECIALLY STRONG
THROUGH MOUNTAIN PASSES ALONG THE ALASKA RANGE AND CHUGACH MOUNTAIN
ON WEDNESDAY THEN DIMINISH THURSDAY.

.SOUTHWEST ALASKA...SKIES WILL BECOME MOSTLY CLEAR OVERNIGHT AS THE
RIDGE MOVES INTO WESTERN ALASKA. WINDS WILL DIMINISH FROM THE WEST
TONIGHT AND THURSDAY. CLOUDS AND POSSIBLY SOME RAIN WILL MOVE INTO
THE KUSKOKWIM DELTA THURSDAY.

BERING SEA AND ALEUTIANS...A STORM SYSTEM OVER NORTHWEST PACIFIC WILL
TURN NORTH INTO THE WESTERN BERING THROUGH THURSDAY. AN ASSOCIATED
WEATHER FRONT OVER THE WESTERN BERING AND WESTERN ALEUTIANS WILL MOVE
INTO THE EASTERN BERING AND EASTERN ALEUTIANS THURSDAY. RAIN AND GALE
FORCE WINDS WITH AREAS OF STORM FORCE GUSTS AHEAD OF THE FRONT WILL
MOVE INTO THE CENTRAL ALEUTIANS AND BERING WEDNESDAY AND WILL
DIMINISH A LITTLE AS IT MOVES INTO THE EASTERN BERING.

.LONG TERM FORECAST...
THE UPPER RIDGE OVER WESTERN ALASKA WILL WEAKEN AS IT MOVES INTO
SOUTHCENTRAL ALASKA SATURDAY. MOSTLY CLEAR WEATHER WILL PERSIST OVER
SOUTHCENTRAL ALASKA THROUGH SATURDAY. THE WEATHER FRONT OVER THE
EASTERN BERING WILL STALL OVER EASTERN ALEUTIANS AND ALONG THE
KUSKOKWIM DELTA COAST FRIDAY THEN MOVE INTO BRISTOL BAY AND THE
ALASKA PENINSULA SATURDAY AND WEAKEN OVER THE WESTERN GULF SUNDAY.
RAIN ASSOCIATED WITH THE FRONT WILL PUSH INTO SOUTHWEST ALASKA AND
KODIAK ISLAND SATURDAY AND POSSIBLE INTO THE KENAI PENINSULA AND
SUSITNA VALLEY SUNDAY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 121 130 132 150 172 175 176 179 185
FIRE WEATHER...RED FLAG WARNING FOR THE WESTERN KENAI PENINSULA.

NM MAY 11