Blizzard in Alaska, January 27 to 29, 2012

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKST FRI JAN 27 2012

.MODEL DISCUSSION...MODELS IN GENERAL ARE IN FAIR AGREEMENT WITH
SYNOPTIC FEATURES THROUGH THE SHORT TERM. AFTERNOON PACKAGES WILL BE
BASED ON THE GFS AND NAM.

.UPPER LEVELS...
WEAK SOUTHWESTERLY FLOW ASSOCIATED WITH A EASTWARD MOVING SHORT WAVE
WAS EVIDENT OVER THE MAINLAND. A WELL DEFINED SHORT WAVE OVER THE
NORTHEAST PACIFIC WAS MOVING RAPIDLY ENE TOWARD THE QUEEN CHARLOTTE
ISLANDS. A LARGE LOW CENTER WAS LOCATED SOUTH OF THE WESTERN ALEUTIAN
ISLANDS.

THE LOW SOUTH OF THE ALEUTIANS WILL MAINTAIN ITS INTENSITY AS IT
HEADS TOWARD THE CENTRAL ALEUTIANS THROUGH SAT...THEN BECOME DIFFUSE
AS IT WEAKENS OVER THE BERING SEA SUN NIGHT. WESTERLY FLOW OVER THE
MAINLAND SAT WILL BECOME MORE SOUTHWESTERLY AS SHORT WAVES RIPPLE
ACROSS THE REGION. A FAIRLY SIGNIFICANT SHORT WAVE MOVING ACROSS THE
NORTH PACIFIC IMPACTS THE WESTERN GULF ON SUN NIGHT.

.SHORT TERM FORECAST...

.SOUTHCENTRAL ALASKA...A WEATHER FRONT APPROACHING THE SOUTHERN GULF
OF ALASKA WILL BRING SNOW AND WINDY CONDITIONS TO KODIAK TONIGHT AND
SAT. WINDS LOOK TO BE BELOW BLIZZARD LEVELS BUT WITHIN THE WEATHER
ADVISORY CATEGORY. INCREASING PRESSURE GRADIENTS ON SAT COULD PRODUCE
SOME LOCAL WIND CHILLS CONDITIONS ACROSS THE SUSITNA VALLEY. A STRONG
LOW MOVING NEAR KODIAK ISLAND SUN AND SUN NIGHT WILL BRING WIND AND
INCREASING CHANCES OF PRECIPITATION TO MUCH OF KODIAK AND THE GULF
COASTS. PRECIPITATION WILL START AS SNOW NEAR KODIAK ON SUN...THEN
BECOME MIXED WITH RAIN BY LATE AFTERNOON.

SOUTHWEST ALASKA...WEAK HIGH PRESSURE WILL MOVE NORTH TONIGHT. NORTH
WINDS WILL INCREASE ACROSS THE REGION IN RESPONSE TO INTENSIFYING
PRESSURE GRADIENTS TONIGHT AND SAT. WINDY CONDITIONS COMBINED WITH
COLD AMBIENT TEMPS WILL PRODUCE LOW WIND CHILLS. MOISTURE ASSOCIATED
WITH A WEATHER FRONT MOVING EAST ACROSS THE BERING SEA WILL BRING
INCREASING CHANCES OF SNOW ALONG WITH WARMING TEMPERATURES SAT NIGHT
AND SUN.

.ALEUTIANS AND AK PEN...THE MAIN CONCERNS ARE BLIZZARD CONDITIONS
ACROSS THE ALEUTIANS AND PORTIONS OF THE AK PEN ASSOCIATED WITH A LOW
COMPLEX SOUTH OF THE ALEUTIANS AND ITS NORTH AND EAST ADVANCING
FRONTAL TROUGH. STRONG WINDS AND BLOWING SNOW WILL LIKELY MOVE INTO
THE CENTRAL AND EAST ALEUTIANS THIS EVENING THEN SHOULD END SAT AS
SNOW BECOMES MIXED WITH RAIN. FURTHER EAST...THE EASTWARD EXTENSION
OF THE FRONT BRINGS A SHOT AT BLIZZARD CONDITIONS TO THE AK PEN SAT
MORNING. BLIZZARD CONDITIONS SHOULD END IN THE AFTERNOON AS TEMPS
WARM AND SNOW BECOMES MIXED WITH RAIN.

.LONG TERM FORECAST...
MODEL AGREEMENT WITH SURFACE FEATURES IS DECENT THROUGH ABOUT TUESDAY
NIGHT BEFORE THERE ARE SIGNIFICANT DIFFERENCES. LOOKS LIKE A MORE
ACTIVE PERIOD NEXT WEEK FOR SOUTH CENTRAL AK ESPECIALLY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WARNING 181 185 187.
MARINE...GALE WARNING 130 138 155 160 165 170 172 175 176 179
                      185 411 412 413 414.

RMC JAN 12