Small Craft Advisory 850, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 PM AKST WED NOV 23 2011

.ANALYSIS AND UPPER LEVELS...THE COLD UPPER LEVEL LOW REMAINS OVER
THE INTERIOR OF THE STATE AND WELL INTO THE BERING SEA. THE 250 MB
JET STREAM IS RUNNING WEST TO EAST BUT REMAINING SOUTH OF THE STATE.
WITH OUT THE UPPER LEVEL SUPPORT THE COMPLEX LOW IN THE GULF HAS
FILLED WITH COLD AIR WITH MULTIPLE SMALLER EMBEDDED LOWS.

.MODEL DISCUSSION...THE BIGGEST THING THAT JUMPS OUT IN LOOKING AT
THE MODELS FROM THE 12Z RUNS IS HOW THE GFS HAS OVER SMOOTHED THE
FEATURES OF THE COMPLEX LOW IN THE GULF. THAT CONTINUES FOR THE NEXT
FEW DAYS WITH THE GULF LOW. THE NAM AND ECMWF HAVE MORE DISTINCT
FEATURES IN THIS LOW COMPLEX AND THE NAM WAS USED IN THE EASTERN HALF
OF THE FORECAST AREA. IN THE BERING SEA REGION THE GFS DID NOT HAVE
THE SAME ISSUES AND FORECAST WAS NUDGED A LITTLE THAT WAY.

.SHORT TERM FORECAST...GUSTY OUTFLOW WINDS ALONG THE GULF COAST AND
THE ALASKA PENINSULA WILL CONTINUE INTO THURSDAY. SNOW SHOWERS WILL
CONTINUE ON AND OFF ALONG THE GULF COAST WITH A FEW SNEAKING A LITTLE
FARTHER INLAND. OVERALL SOUTH CENTRAL ALASKA WILL SEE PARTLY TO
MOSTLY CLOUDY SKIES IN THE NORTH TO NORTHWEST FLOW THAT CONTINUES TO
BRING IN COLD AND DRY AIR.
SOUTHWEST ALASKA IS IN THE SAME SITUATION WITH NORTHWEST FLOW ALOFT
AND AT THE SURFACE. THERE WILL BE A FEW AREA OF FLURRIES AS THE AIR
IS COLD ENOUGH THAT VERY LITTLE LIFT WILL CAUSE THE MOISTURE TO
PRECIPITATE OUT.
TEMPERATURES ARE MODERATED ALONG THE ALEUTIAN ISLANDS AND SOME WEAK
LOWS WILL TRAVERSE THE AREA. PRECIPITATION TYPE WILL MOSTLY BE SNOW
SHOWERS, HOWEVER THE WILL BE SOME RAIN MIXED IN THE PRECIPITATION IN
THE CENTRAL ALEUTIANS.

.LONG TERM FORECAST...
COLD FOR MOST OF THE STATE CONTINUES THROUGH THE WEEKEND. MODELS
CONTINUE TO INDICATE A PATTERN CHANGE BEGINNING AROUND SUNDAY AS THE
LONGWAVE TROUGH IN THE GULF SHIFTS WESTWARD INTO THE BERING SEA. THIS
WILL ALLOW A RETURN TO MORE SEASONABLE TEMPERATURES AND MORE ACTIVE
WEATHER ACROSS MAINLAND ALASKA.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 155 160 165 175 176 180.
         HEAVY FREEZING SPRAY 129 130 138 140 150 160 179 180 185.
FIRE WEATHER...NONE.

NOV 11