Small Craft Advisory 69, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AKST MON JAN 19 2009

.ANALYSIS AND UPPER LEVELS...THE SYNOPTIC PATTERN IS UNCHANGED FROM
YESTERDAY...WITH THE TROUGH REMAINING OVER THE BERING SEA AND THE
RIDGE HOLDING STRONG OVER WESTERN NORTH AMERICA. THE REMNANTS OF THE
OCCLUDED LOW ARE APPROACHING THE KENAI PENINSULA FROM THE SOUTH AND
WILL MOVE OFF TO THE NORTHEAST TODAY. A STRONG LOW SOUTH OF THE
CENTRAL ALEUTIANS WILL DRIFT NORTHEAST TODAY AS IT BREAKS UP INTO
SEVERAL CIRCULATIONS.

.MODEL DISCUSSION...MODELS ARE IN PRETTY GOOD SYNOPTIC AGREEMENT
THROUGH ABOUT 72 HOURS. BY THE END OF THIS WEEK THE GFS WANTS TO
MAINTAIN A STRONG RIDGE OVER EASTERN ALASKA AND THE NORTHEAST
PACIFIC. MEANWHILE THE EUROPEAN MODEL HAS BEEN CONSISTENT IN SHOWING
THAT RIDGE PINCHING OFF INTO A CLOSED HIGH OVER NORTHERN
ALASKA...ALLOWING SYSTEMS TO ENTER THE GULF OF ALASKA. THE THOUGHT AT
THIS TIME IS THAT THE RIDGE WILL BREAK...SO THE MORNING FORECASTS ARE
BASED ON THE 00Z ECMWF IN THE MID AND LONG RANGE...AND THE GFS/NAM IN
THE SHORT TERM.

.SHORT TERM FORECAST...
.SOUTHCENTRAL...MOST AREAS WILL SEE RAIN AND SNOW SHOWERS
TODAY...ENDING FROM SOUTHWEST TO NORTHEAST THIS EVENING AND TONIGHT.
PRINCE WILLIAM SOUND AND POINTS EASTWARD ALONG THE COAST WILL SEE
MUCH STEADIER AND HEAVIER PRECIP CONTINUE TODAY. FORTUNATELY MOST
AREAS WILL SEE RAIN OR A MIX OF RAIN AND SNOW...SO ACCUMULATIONS WILL
NOT BE A TREMENDOUS CONCERN EXCEPT AT HIGHER ELEVATIONS SUCH AS
THOMPSON PASS WHERE THE BLIZZARD WILL LIKELY CONTINUE THROUGH THE
MORNING HOURS.

.SOUTHWEST ALASKA...LIGHT SNOW ENDING THIS MORNING EAST OF KING
SALMON. UP INTO THE KUSKOKWIM VALLEY SNOW WILL PERSIST THROUGH LATE
AFTERNOON WITH A FEW INCHES OF ADDITIONAL ACCUMULATION LIKELY.

.BERING SEA/ALEUTIANS...THE STORM SOUTH OF THE ALEUTIANS WILL SPREAD
STRONG WINDS AND PRECIP NORTH AND EAST TODAY AND TONIGHT.
FORTUNATELY...WARM AIR AHEAD OF THIS FEATURE WILL MEAN MOST AREAS
WILL TURN TO RAIN QUICKLY...WITH THE EXCEPTION OF THE PRIBILOF
ISLANDS. THUS...THE MAIN IMPACT FOR MOST LOCATIONS WILL BE THE STRONG
WINDS ON THE FRONT AND BACKSIDE OF THIS FEATURE.

.LONG TERM FORECAST...WEATHER FOR MUCH OF MAINLAND ALASKA WILL CALM
DOWN FOR SEVERAL DAYS STARTING TUESDAY. THE BERING SEA AND ALEUTIAN
ISLANDS WILL REMAIN IN A MORE ACTIVE WEATHER PATTERN...THOUGH MOST OF
THE INTENSE STORMS WILL STAY SOUTH OF THE CHAIN AND ONLY MOVE INTO
THE BERING AS DECAYING LOWS.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD 131
MARINE...GALE WARNING 155 170 172 175 179 185
FIRE WEATHER...NONE

AMD JAN 09