Small Craft Advisory 19, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKST SAT JAN 4 2014

.ANALYSIS AND UPPER LEVELS...
THERE IS AN UPPER LEVEL LOW SOUTH OF THE ALASKA PENINSULA AND
EASTERN ALEUTIANS AND AN UPPER (BLOCKING) HIGH ALONG THE
U.S./CANADIAN WEST COAST STRETCHING ACROSS THE ALASKA PANHANDLE INTO
THE SOUTHEAST CORNER OF ALASKA. BETWEEN THESE TWO FEATURES IS A LONG
SOUTHERLY FETCH OF MOISTURE PUSHING INTO SOUTHERN ALASKA. THERE IS A
MULTIPLE CENTER LOW WEST OF THE ALEUTIANS.

.SHORT TERM FORECAST...
FOR SOUTH CENTRAL ALASKA...MOIST SOUTHERLY FLOW WILL CONTINUE
THROUGH TONIGHT. THE SOUTHERLY FLOW WILL WEAKEN SUNDAY AND THE
MOISTURE WILL MOVE OFF TO THE EAST AS THE WEST COAST HIGH "RELAXES"
AND THE ALASKA PENINSULA LOW SEPARATES FROM THE MOISTURE AND MOVES
NORTHWEST. MOST OF THE PRECIPITATION TONIGHT WILL BE IN COASTAL
AREAS...AS WELL AS INLAND IN THE COPPER RIVER BASIN WHICH IS UNDER
THE MAIN STREAM OF MOISTURE. COLD TEMPERATURES OVER THE COPPER RIVER
BASIN WILL ALSO CAUSE SOME "VIRTUAL TERRAIN" TO LESSEN DOWN-SLOPE
EFFECTS. THINGS WILL QUIET DOWN THROUGH SUNDAY...BUT WITH CONTINUED
SOUTHERLY FLOW THERE WILL STILL BE PLENTY OF CLOUDS AND SOME
PRECIPITATION...AGAIN MAINLY IN COASTAL AREAS. THIS GENERAL PATTERN
WILL CONTINUE TO BRING CHANCES OF PRECIPITATION THROUGH TUESDAY.

PRECIPITATION TYPE WILL BE AN ISSUE THROUGH TUESDAY. PLENTY OF WARM
AIR ALOFT WILL INCREASE THE CHANCES OF LIQUID PRECIPITATION (RAIN)
RATHER THAN FROZEN (SNOW) FOR LOW-LAND AREAS NEAR COOK INLET. 850 MB
TEMPERATURES OVER ANCHORAGE ARE FORECAST BY THE GFS TO CLIMB TO
ABOVE ZERO DEGREES CENTIGRADE EARLY SUNDAY MORNING THEN SLOWLY DROP
STARTING SUNDAY AFTERNOON...BUT STAY ABOVE -3C THROUGH TUESDAY
AFTERNOON.

FOR SOUTHWEST ALASKA...WARM MOIST AIR WILL CONTINUE TO SPREAD ACROSS
THE AREA TONIGHT. WARM AIR ALOFT WILL CONTINUE THROUGH TUESDAY
AFTERNOON...THOUGH SOME COOLER AIR WILL MOVE THROUGH LATE SUNDAY
NIGHT AND TUESDAY WITH THE PASSAGE OF A WEAK UPPER TROUGH ASSOCIATED
WITH THE LOW THAT IS CURRENTLY SOUTH OF THE EASTERN ALEUTIANS/ALASKA
PENINSULA BUT AT THIS TIME WILL HAVE MOVED OVER TO THE CENTRAL
BERING SEA. PRECIPITATION TYPE THROUGH TUESDAY WILL BE A CHALLENGE
WITH SNOW...RAIN...AND EVEN FREEZING RAIN POSSIBLE.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...WINTER STORM WARNING 131 (T-PASS).
MARINE...STORM WARNING 119.
         GALE WARNING 120 125 129 130 131 138 139 150 155 160 170
                   171 172 178 180 181 185.
         HEAVY FREEZING SPRAY 180 181 185.
FIRE WEATHER...NONE.

LUDWIG JAN 14