Small Craft Advisory 687, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 PM AKDT FRI SEP 23 2011

.ANALYSIS AND UPPER LEVELS...
A BROAD AREA OF LOW PRESSURE CONTINUES TO COVER MOST OF THE STATE.
THE FLOW OVER THE GULF HAS BECOME WEST TO NORTHWEST WHICH HAS ALLOWED
PARTS OF THE SOUTHERN MAINLAND TO DRY OUT A LITTLE. THE FORMER
TYPHOON ROKE HAD MOVED INTO THE WESTERN ALEUTIANS AND HAS BROUGHT
GUSTY WINDS AND RAIN TO THE AREA.

.MODEL DISCUSSION...
THE MODELS ARE IN VERY GOOD AGREEMENT THOUGH THE GFS IS PREFERRED IN
THE GULF BECAUSE IT FORMS A CLOSED LOW OVER THE WESTERN GULF A LITTLE
FASTER THE THE OTHER MODELS. THE ECMWF STILL APPEARS TO BE HANDLING
THE LOW MOVING THROUGH THE ALEUTIANS THE BEST.

.SHORT TERM FORECAST...
.SOUTHCENTRAL ALASKA AND THE GULF...A WEAK LOW WILL DEVELOP OVER THE
WESTERN GULF TONIGHT THEN SLOWLY DRIFT SOUTH INTO THE NORTH PACIFIC
MONDAY. A RIDGE OF HIGH PRESSURE WILL BUILD BACK ALONG THE CENTRAL
GULF COAST TONIGHT. THIS PATTERN WILL SWITCH THE WIND OVER THE GULF
BACK TO THE SOUTH AND SOUTHEAST LATE TONIGHT THEN TO THE EAST AND
NORTHEAST SATURDAY NIGHT. RAIN SHOWERS WILL WORK BACK INTO THE
CENTRAL GULF COAST TONIGHT THEN DIMINISH AGAIN SATURDAY NIGHT.
SCATTERED AFTERNOON AND EVENING SHOWERS WILL DEVELOP OVER THE
INTERIOR SECTIONS OVER THE WEEKEND.

.SOUTHWEST ALASKA...A WEAK TROUGH EXTENDED FROM THE WESTERN GULF
THROUGH SOUTHWEST ALASKA THOUGH A DRY NORTHEAST FLOW OVER THE
INTERIOR SECTIONS HAS KEPT THE KUSKOKWIM VALLEY AND EASTERN BRISTOL
BAY MOSTLY SUNNY. SCATTERED AFTERNOON AND EVENING SHOWERS WILL
DEVELOP ALONG THE EASTERN MOUNTAINS THROUGH THE WEEKEND. AREAS OF LOW
CLOUDS AND FOG OVER THE KUSKOKWIM DELTA WILL PROBABLE PERSIST THROUGH
THE WEEKEND.

.BERING SEA AND ALEUTIANS...THE LOW OVER THE WESTERN ALEUTIANS WILL
MOVE THROUGH THE CENTRAL ALEUTIANS TONIGHT THEN TURN SOUTHEAST INTO
THE CENTRAL PACIFIC SATURDAY. WEST TO NORTHWEST FLOW WILL DOMINATE
THE BERING THROUGH THE WEEKEND.

.LONG TERM FORECAST...
THE FORMER TYPHOON ROKE OVER THE NORTHEAST PACIFIC SUNDAY NIGHT WILL
TURN NORTHEAST AND MOVE INTO SOUTHEAST ALASKA TUESDAY BEFORE
DISSIPATING OVER WESTERN CANADA WEDNESDAY. ANOTHER LOW DEVELOPING
OVER SIBERIA SUNDAY WILL MOVING INTO THE CENTRAL BERING MONDAY THEN
MOVE ACROSS THE ALASKA PENINSULA EARLY TUESDAY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.

NM SEP 11