Small Craft Advisory 722, NWS Anchorage, AK

AREA FORECAST DISCUSSION...CORRECTION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 PM AKDT FRI SEP 19 2008

CORRECTION FOR TYPOS

.MODEL DISCUSSION...
MODELS ARE IN GOOD AGREEMENT THROUGH SUNDAY NIGHT THOUGH THE NAM
APPEARS TO HANDLE THE SITUATION IN THE GULF BEST FOR THE FIRST 24 TO
36 HOURS.

.ANALYSIS AND UPPER LEVELS...
THE STRONG UPPER LOW OVER KODIAK ISLAND HAS WEAKENED INTO A TROUGH
OVER THE KENAI PENINSULA AND THE MAIN CENTER HAS SHIFTED INTO THE
LOWER YUKON VALLEY OVERNIGHT. A STRONG VORTICITY MAX OVER PRINCE
WILLIAM SOUND, MATANUSKA VALLEY AND SUSITNA VALLEY APPEAR TO BE
ASSOCIATED WITH A 300 MB JET AND BOTH ARE MOVING NORTHEAST.

THOUGH THE SURFACE LOW HAS SIGNIFICANTLY WEAKENED SINCE YESTERDAY,
THE WEATHER FRONT HAS REMAINED FAIRLY STRONG WITH THE SUPPORT OF THE
UPPER VORTICITY MAX AND THE 300 MB JET. A WIDE SWATH OF RAIN
CONTINUES TO FALL ACROSS PRINCE WILLIAM SOUND, MATANUSKA VALLEY,
COPPER RIVER BASIN AND THE SUSITNA VALLEY TODAY.

A TROUGH OF LOW PRESSURE REMAINS OVER MOST OF WESTERN ALASKA TODAY.
SKIES CONTINUE BE CLOUDY WITH SCATTERED SHOWERS OVER SOUTHWEST
ALASKA.

.SHORT TERM FORECAST...
UPPER AIR...THE UPPER LOW OVER THE LOWER YUKON VALLEY WILL SLOWLY
MOVE INTO THE CENTRAL INTERIOR BY SUNDAY NIGHT. THE TROUGH AND
VORTICITY MAX EXTENDING SOUTHEAST OF THE CENTER WILL SWING NORTH
THROUGH THE SOUTHCENTRAL MAINLAND TONIGHT AND INTO THE NORTHERN
INTERIOR SATURDAY AFTERNOON. ANOTHER SHORT-WAVE TROUGH DEVELOPING
OVER SOUTHWEST ALASKA TONIGHT WILL MOVE INTO THE KENAI PENINSULA AND
SUSITNA VALLEY BY LATE SATURDAY AND INTO THE WESTERN COPPER RIVER
BASIN AND PRINCE WILLIAM SOUND SUNDAY NIGHT. A SHALLOW RIDGE WILL
REMAIN OVER THE BERING SEA AND EXTEND INTO WESTERN ALASKA SUNDAY.

SURFACE...A WEAK LOW DEVELOPING OVER THE CENTRAL INTERIOR THIS
EVENING WILL MOVE INTO THE NORTHERN INTERIOR SATURDAY AND CONTINUE
INTO THE BEAUFORT SEA SUNDAY. THE WEATHER FRONT OVER SOUTHCENTRAL
ALASKA WILL SWING NORTH INTO THE TANANA VALLEY AND UPPER YUKON
VALLEY BY SATURDAY MORNING AND INTO NORTHEAST ALASKA SUNDAY. A RIDGE
OVER THE SOUTHEAST BERING SEA WILL MOVE INTO SOUTHWEST ALASKA
SATURDAY NIGHT. A TROUGH OVER THE WESTERN BERING WILL EXTEND EASTWARD
INTO CENTRAL BERING SATURDAY AND WILL PERSIST THROUGH SUNDAY.

SOUTHCENTRAL ALASKA AND THE GULF...RAIN ALONG THE FRONT WILL MOVE
NORTH THROUGH TONIGHT AND WILL BECOME SCATTERED SHOWERS BY SATURDAY
MORNING. AREAS OF RAIN ASSOCIATED WITH THE UPPER TROUGH OVER
SOUTHWEST ALASKA WILL MOVE INTO THE SUSITNA VALLEY AND KENAI
PENINSULA SATURDAY AND SPREAD INTO THE REST OF REGION BY SUNDAY.

SOUTHWEST ALASKA...AREAS OF RAIN WILL DEVELOP OVER SOUTHWEST INTERIOR
WITH THE DEVELOPMENT OF THE UPPER TROUGH TONIGHT AND WILL CHANGE TO
SHOWERS FROM THE WEST SATURDAY. SHOWERS WILL DIMINISH SUNDAY.

.LONG TERM FORECAST...
A WEAK LOW DEVELOPING WITHIN THE TROUGH OVER THE CENTRAL BERING SEA
SUNDAY NIGHT WILL MOVE INTO SOUTHWEST ALASKA MONDAY AND INTO THE GULF
OF ALASKA BY TUESDAY NIGHT. RAIN WILL MOVE INTO SOUTHWEST ALASKA
MONDAY AND INTO KODIAK ISLAND AND THE GULF MONDAY NIGHT AND TUESDAY.
THE RIDGE OVER SOUTHWEST ALASKA WILL BUILD INTO THE CENTRAL INTERIOR
MONDAY BUT WILL WEAKEN AS THE SURFACE LOW CUTS THROUGH ON TUESDAY.
HIGH PRESSURE BUILDS INTO NORTHERN ALASKA WEDNESDAY.

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

NM SEP 08