Small Craft Advisory 967, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
400 AM AKST SAT DEC 6 2008

.ANALYSIS AND UPPER LEVELS...
AT UPPER LEVELS THIS MORNING IS A TROUGH OVER EASTERN ASIA...A RIDGE
OVER THE WESTERN BERING/ALEUTIANS...AND A TROUGH OVER THE EASTERN
BERING AND THE MAINLAND. THE PATTERN IS HIGHLY AMPLIFIED WITH THE
TROUGHS EXTENDING SOUTH INTO THE TROPICS AND THE RIDGE EXTENDING
NORTH INTO THE ARCTIC OCEAN. GETTING INTO A LITTLE MORE
DETAIL...THERE IS A SURFACE LOW JUST EAST OF ATKA RACING SOUTH INTO
THE NORTH PACIFIC ALONG A NORTHERLY UPPER JET. THIS LOW STILL HAS
SOME LINGERING STORM FORCE WINDS ON ITS NORTHWEST SIDE. ANOTHER
SURFACE LOW IS POSITIONED IN THE FAR WESTERN GULF JUST SOUTH OF
CHIGNIK. THIS WEAK LOW IS MORE DETACHED FROM THE UPPER LEVEL JET AND
WILL SLOWLY MOVE NORTHEAST INTO THE NORTHERN GULF OF ALASKA AND
CONTINUE TO WEAKEN. A VERY MILD AIRMASS IS IN PLACE FROM THE EASTERN
BERING EAST INTO THE SOUTHERN MAINLAND...BUT AN UPPER LEVEL
SHORTWAVE TROUGH OVER THE SEWARD PENINSULA THIS MORNING MOVING SOUTH
WILL BRING A GRADUAL RETURN TO COLD TEMPERATURES FOR MOST OF THE
AREA.

.MODEL DISCUSSION...
MODELS ARE IN PRETTY GOOD AGREEMENT OVERALL THROUGH ABOUT THURSDAY.
THE MAIN MODEL ISSUE IS AND WILL LIKELY CONTINUE TO BE A MAJOR GULF
LOW MONDAY THROUGH WEDNESDAY. GFS CONTINUES TO HAVE RUN TO RUN
CONSISTENCY ISSUES AND THUS WE WILL CONTINUE TO FAVOR THE ECMWF.

.SHORT TERM FORECAST...
SOUTHCENTRAL...
MOST IMMEDIATE CONCERN IS FREEZING RAIN. ANCHORAGE SOUNDING
CONTINUES TO BE VERY FAVORABLE FOR FREEZING RAIN...BUT THANKFULLY
PRECIPITATION HAS BEEN QUITE LIGHT. WILL CONTINUE TO KEEP AN EYE OUT
FOR ANY HEAVIER PRECIPITATION MAKING IT TO PORTIONS OF THE COOK
INLET REGION WHICH ARE STILL BELOW FREEZING. THE ATMOSPHERE SHOULD
BEGIN TO GRADUALLY COOL TONIGHT WITH THE FREEZING RAIN THREAT GOING
AWAY. WEAK LOW PRESSURE WILL MOVE FROM THE FAR WESTERN GULF TO JUST
SOUTH OF SEWARD AND GRADUALLY DISSIPATE SUNDAY AND SUNDAY NIGHT. ANY
SNOW SUNDAY AND SUNDAY NIGHT SHOULD GENERALLY BE LIGHT WITH THE
POSSIBLE EXCEPTION OF THE COPPER RIVER BASIN...WHERE A DECENT
OVERRUNNING SNOW EVENT SHOULD SET UP. A STRONG LOW PRESSURE SYSTEM
WILL MOVE NORTHEAST INTO THE SOUTHWEST GULF OF ALASKA MONDAY AND
WILL BE A MAJOR PLAYER FOR SOUTHCENTRAL THROUGH WEDNESDAY.

SOUTHWEST MAINLAND...
ANY REMAINING PRECIPITATION OVER THE SOUTHWEST MAINLAND SHOULD TAPER
OFF BY MIDDAY SUNDAY AS COLDER DRIER AIR WORKS IN FROM THE NORTH.
THROUGH TONIGHT...MOST OF THE PRECIPITATION AROUND BRISTOL BAY WILL
FALL AS RAIN OR A RAIN SNOW MIX...WHILE THE KUSKOKWIM DELTA COULD
CONTINUE TO SEE SOME FREEZING RAIN THIS MORNING BEFORE COLDER DRIER
AIR MOVES IN THIS AFTERNOON.

BERING SEA/ALEUTIANS...
THE LOW JUST EAST OF ATKA WILL RACE INTO THE NORTH PACIFIC
TODAY...ALLOWING FOR STRONG COLD ADVECTION FROM THE CENTRAL
BERING/ALEUTIANS EAST. HIGH PRESSURE IN THE WESTERN BERING/ALEUTIANS
THIS MORNING WILL RAPIDLY PROGRESS EAST AS A FRONT MOVES EAST INTO
THE WESTERN BERING/ALEUTIANS SUNDAY AND SUNDAY NIGHT. THIS FRONT
WILL HAVE TROUBLE MOVING ANY FURTHER EAST THAN ABOUT 173W AS IT HITS
THE RIDGE OF HIGH PRESSURE AND SOME OF THE ENERGY IS ABSORBED INTO
THE STRENGTHENING GULF LOW.

.LONG TERM FORECAST...
FROM WEDNESDAY INTO THURSDAY...EXPECT LOW PRESSURE OVER THE NORTHERN
GULF OF ALASKA...HIGH PRESSURE OVER THE EASTERN BERING...AND LOW
PRESSURE IN THE FAR WESTERN BERING. THE MODELS FALL APART BEYOND
THURSDAY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...STORM WARNING ZONES 412 413.
         GALE WARNING ZONES 172 175 185 411.
         HEAVY FREEZING SPRAY WARNING 180 185.
FIRE WEATHER...NONE.

FOISY DEC 08