Blizzard in Alaska, February 14 to 15, 2012

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ANCHORAGE AK
540 PM AKST TUE FEB 14 2012

UPDATED SOUTHCENTRAL/SOUTHWEST AND WATCH/WARNING SUMMARY...
HAVE ISSUED BLIZZARD WATCHES WITH AFTERNOON PACKAGE FOR PORTAGE
VALLEY/TURNAGAIN ARM AND THOMPSON PASS REGIONS. MARGINALLY COLD
TEMPERATURES COUPLED WITH STRENGTHENING WINDS AHEAD OF THE GULF FRONT
MAY BRING A PERIOD OF POOR VISIBILITY FROM BLOWING SNOW WEDNESDAY
AFTERNOON THROUGH EVENING.

ACROSS THE SOUTHWEST MAINLAND...HAVE ISSUED WINTER WEATHER ADVISORIES
FOR BLOWING SNOW FOR ALONG COASTAL AREAS OF THE KUSKOKWIM DELTA AND
AREAS NORTH AND WEST OF DILLINGHAM IN BRISTOL BAY. CONDITIONS LOOK TO
IMPROVE MID DAY WEDNESDAY AS WINDS WEAKEN AND ALLOW THE BLOWING SNOW
THREAT TO DIMINISH.

.MODEL DISCUSSION...NAM AND GFS AS WELL AS EC IN REASONABLE AGREEMENT
ON SOLUTION FOR THE FIRST 42 HOURS BUT THEN THERE IS MAJOR
DIVERGENCE. ALL MODELS KEEP THE ALEUTIAN STORM CENTERED OVER THE
EASTERN ALEUTIANS AND THEN SLOWLY MOVE IT TO THE NORTHWEST ON
THU...THE NAM IS A BIT DEEPER THAN THE OTHER TWO MODELS BUT NOT THAT
MUCH. THE SOLUTIONS DIVERGE WITH THE NEXT NORTH PACIFIC LOW THAT
MOVES INTO THE GULF THU NIGHT. THE EC SEEMS TO BE THE OUTLIER OF THE
GROUP WITH A WASHED OUT LOW.  THE GENERAL IDEA IS A 980 MB SOMETHING
LOW STRADDLING 150W WHICH MOVES INTO THE NORTHERN GULF FRI AFTERNOON.
MAIN IMPACT AT CURRENT TIME IS FOR THE MARINE WINDS AND KODIAK
ISLAND.

.ANALYSIS AND UPPER LEVELS...FRONT THAT MOVED THROUGH SOUTHCENTRAL
MON NIGHT HAS MOVED OFF INTO THE EASTERN INTERIOR WITH MAINLY SUNNY
SKIES THIS AFTERNOON OVER MOST OF SOUTHCENTRAL. NEXT MAJOR SYSTEM
ALREADY IMPACTING CENTRAL ALEUTIANS THROUGH TO THE AK PEN. LOOKS AS
WINDS WILL REMAIN BELOW WARNING CRITERIA FOR THE DURATION OF THE
EVENT. MODELS HAVE BEEN CONSISTENT IN PARKING THIS SYSTEM OVER THE
EASTERN ALEUTIANS TODAY AND WED BEFORE IT MOVES TO THE NORTHWEST ON
THU. FRONT ASSOCIATED WITH THIS SYSTEM IS MOVING OVER PRIBILOFS THIS
AFTERNOON AND ONSHORE IN THE SOUTHWEST LATER TUE AFTERNOON.

.SHORT TERM FORECAST...
BERING REGION...CLOUDY WITH RAIN OR SNOW FROM CENTRAL ALEUTIANS
EASTWARD. MODERATE TO STRONG WINDS OVER SAME REGION. LITTLE ACTIVITY
IN THE WESTERN AL AND BERING UNTIL THU AFTERNOON WHEN A FRONT MOVES
IN FROM THE NO. PAC.

SOUTHWEST...FRONT SHOULD BE MOVING ONSHORE THIS AFTERNOON STARTING IN
BRISTOL BAY.  LOOKS AS MOST PRECIP SHOULD BE IN THE FORM OF SNOW BUT
SOME MIXED SNOW AND RAIN CERTAINLY POSSIBLE NEAR THE COAST. GFS
INDICATING FONT LINGERS THROUGH MOST OF WED. SOME CLEARING WED NIGHT
AND THU.

SOUTHCENTRAL...GENERALLY SUNNY THIS AFTERNOON AND EVENING WITH FRONT
MOVING INTO COOK INLET THIS EVENING AND ONSHORE NEAR CORDOVA DURING
THE NIGHT. LOOKING FOR SNOW TURNING TO RAIN BY WED MORNING ALONG THE
COAST WITH SNOW INLAND.  KODIAK RAINY THROUGH WED PM WITH A SHORT
BREAK WED NIGHT BEFORE NEXT SYSTEM MOVES THROUGH SOMETIME LATE THU
MORNING.

.LONG TERM FORECAST...WITH THE MODEL UNCERTAINTY IT IS DIFFICULT TO
BE VERY PRECISE. THE OVERALL SYNOPTIC UPPER LEVEL FLOW ALONG 50N IS
FROM THE WEST TO SOUTHWEST. THE LOW THAT MOVES INTO THE WESTERN AL
THU LINGERS THROUGH THE WEEKEND WITH LITTLE MOVEMENT. CURRENT GFS RUN
SHOWS LITTLE ACTIVITY IN THE GULF OR EASTERN BERING UNTIL LATER ON
SUN.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WARNING...195
         BLIZZARD WATCH...125 131
         WINTER WEATHER ADVISORY FOR BLOWING SNOW...155 161
MARINE...STORM...130 172
         GALE...120 132 138 150 155 160 165 170 171 175 179 180 351
                352 412 413 414
         HEAVY FREEZING SPRAY...NONE
FIRE WEATHER...NONE

JMP/JAM FEB 12