Small Craft Advisory 1077, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM AST WED NOV 22 2006

.DISCUSSION...
ALOFT...THE STRONG PERSISTENT UPPER RIDGE THAT HAS PERSISTED OVER THE
BERING SEA FOR MOST OF NOVEMBER IS FORECAST TO MOVE EAST TO THE
WESTERN ALASKA MAINLAND BY FRIDAY AND TO THE EASTERN MAINLAND BY
SUNDAY.  A MODERATELY STRONG UPPER LOW IS FORECAST TO MOVE FROM THE
WESTERN PACIFIC TO THE CENTRAL BERING SEA BY FRI NIGHT.  A SECOND
STRONGER UPPER TROUGH IS EXPECTED TO MOVE FROM THE WESTERN PACIFIC TO
THE CENTRAL ALEUTIANS BY LATE SAT.  THE DOWNSTREAM UPPER TROUGH OVER
THE EASTERN GULF OF ALASKA IS FORECAST TO MOVE TO VANCOUVER ISLAND BY
SAT.  TODAY AN UPPER JET EXTENDS FROM KOTZBUE SOUND TO THE KENAI
PENINSULA.  THE JET IS EXPECTED TO WEAKEN AND MOVE OVER PRINCE
WILLIAM SOUND BY LAT THU.  SEVERAL WEAK SHORT WAVES WILL MOVE FROM
NORTHERN ALASKA INTO THE GULF THE NEXT TWO DAYS.  EACH ONE OF THESE
WEAK UPPER SYSTEMS WILL INCREASE GUSTY SURFACE WINDS IN GAPS AND
PASSES MAINLY IN PRINCE WILLIAM SOUND.

SURFACE...A RIDGE FROM BARROW TO DAWSON WILL MOVE SLOWLY
SOUTHEASTWARD TO EXTEND FROM DEADHORSE TO WHITEHORSE BY FRI AND TO A
STRONG HIGH OVER NORTHERN BRITISH COLUMBIA BY SUNDAY. MODERATELY
STRONG SURFACE PRESSURE GRADIENTS WILL PERSIST OVER PRINCE WILLIAM
SOUND INTO FRIDAY.  A MODERATELY STRONG LOW NEAR ATTU IS FORECAST TO
REMAIN STATIONARY AND DEEPEN UNTIL EARLY FRI AND THEN MOVE TO THE
NORTHWEST BERING BY EARLY SAT.  THIS SYSTEM WILL BRING RAIN SNOW AND
GUSTY WINDS ACROSS THE ALEUTIANS REACHING THE SOUTHWEST COAST BY LATE
FRI.  A SECOND MORE INTENSE LOW WILL MOVE TO THE CENTRAL ALEUTIANS ON
SAT AND NORTH OF SAINT MATTHEW ISLAND BY EARLY SUN.  WE WILL BE
WATCHING THIS LOW AS IT MAY BE STRONG ENOUGH TO TRIGGER WARNING LEVEL
WINDS TO THE EASTERN ALEUTIANS ALASKA PENINSULA AND POSSIBLY THE
SOUTHWEST COAST SAT AND SUN.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...ICE JAM FLOOD WARNING ZONE 121
MARINE...HEAVY FREEZING SPRAY 121 129 180
         GALE 130 170 175 185 410

RHH NOV 06