Small Craft Advisory 692, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 PM AKDT THU SEP 11 2008

.MODEL DISCUSSION...
MODELS REMAIN IN GOOD AGREEMENT THROUGH SATURDAY AFTERNOON BUT BEGIN
TO HAVE DIVERGENT SOLUTIONS FROM THAT POINT ONWARD. ECMWF CONTINUES
TO MOVE THE NEXT LOW PRESSURE SYSTEM MOVING THROUGH THE ALEUTIANS
THIS WEEKEND FASTER THAN THE OTHER MODELS. GSF CONTINUES TO BE A MORE
CONSISTENT MODEL AND REMAIN IN GOOD AGREEMENT WITH OTHER GLOBAL AND
HEMISPHERIC MODELS.

.ANALYSIS AND UPPER LEVELS...
AN UPPER LOW REMAINS NEARLY STATIONARY OVER THE BEAUFORT SEA WHILE AN
WEAK UPPER RIDGE MOVES INTO THE GULF OF ALASKA. ANOTHER UPPER LOW
OVER THE CENTRAL ALEUTIANS IS VERTICALLY STACKED OVER THE SURFACE LOW
AND BOTH ARE SLOWLY MOVING EAST.

AT THE SURFACE...A WEAK TROUGH EXTENDS ACROSS THE CENTRAL INTERIOR
AND SOUTHWEST ALASKA. THE ATMOSPHERE REMAINS SOMEWHAT UNSTABLE
THROUGH THIS AREA AND SCATTERED SHOWERS ARE EXPECTED TO DEVELOP THIS
AFTERNOON AND EVENING. THE STRONG LOW PRESSURE SYSTEM SOUTH OF THE
CENTRAL ALEUTIANS CONTINUES TO MOVE EAST WITH AN OCCLUDED FRONT
SWINGING NORTHEAST THROUGH THE ALASKA PENINSULA AND SOUTHERN BRISTOL
BAY. AREAS OF RAIN AND GUSTY WINDS MOVE AHEAD OF THE FRONT.

.SHORT TERM FORECAST...
THE UPPER LOW OVER THE THE CENTRAL ALEUTIANS WILL MOVE NORTHEAST INTO
THE ALASKA PENINSULA AND BRISTOL BAY SATURDAY AFTERNOON. THE UPPER
RIDGE OVER THE GULF WILL FORM A BLOCK ALONG SOUTHEAST ALASKA AND THE
YUKON TERRITORY SATURDAY NIGHT.

THE SURFACE LOW WILL REMAIN BENEATH THE UPPER CENTER AS IT MOVES INTO
BRISTOL BAY SATURDAY. THE OCCLUDED FRONT WILL CONTINUE TO MOVE
NORTHEAST THROUGH BRISTOL BAY TONIGHT AND INTO KODIAK ISLAND AND
SOUTHWEST ALASKA FRIDAY. THE FRONT WILL WEAKEN OVER THE SOUTHWEST
INTERIOR FRIDAY NIGHT BUT WILL CONTINUE TO MOVE INTO THE WESTERN GULF
SATURDAY AFTERNOON. RAIN AND WIND WILL MOVE INTO BRISTOL BAY AND
KODIAK ISLAND TONIGHT. RAIN WILL CONTINUE TO SPREAD INTO THE REST OF
SOUTHWEST ALASKA FRIDAY AND BECOME SHOWERS FRIDAY NIGHT AND SATURDAY.
IN THE GULF, RAIN WILL SPREAD UP INTO MOST OF SOUTHCENTRAL ALASKA
WITH THE EXCEPT OF THE EASTERN COPPER RIVER BASIN BY SATURDAY
AFTERNOON.

AN AREA OF GUSTY NORTH WINDS WILL PERSIST OVER THE EASTERN BERING SEA
AND KUSKOKWIM DELTA COAST THROUGH SATURDAY.

ANOTHER LOW PRESSURE SYSTEM NEAR NORTHERN JAPAN WILL MOVE INTO THE
WESTERN ALEUTIANS AS A 990 MB STORM SATURDAY AFTERNOON. MORE RAIN AND
GUSTY WINDS ARE EXPECTED FOR THE WESTERN ALEUTIANS FRIDAY NIGHT AND
SATURDAY.

.LONG TERM FORECAST...
THE UPPER LOW OVER BRISTOL BAY WILL MOVE NORTH AND DISSIPATE OVER THE
KUSKOKWIM DELTA MONDAY.

THE SURFACE WILL MOVE AND DISSIPATE OVER THE YUKON DELTA MONDAY. THE
MODERATE LOW OVER THE WESTERN ALEUTIANS WILL MOVE EAST OVER THE
EASTERN ALEUTIANS MONDAY.

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

NONE SEP 08