Heavy Freezing Spray Warning 45, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKST TUE JAN 17 2012

.MODEL DISCUSSION...MODELS ARE IN GENERALLY GOOD AGREEMENT ON
SYNOPTIC FEATURES THROUGH THE SHORT TERM. DIFFERENCES WHICH DO OCCUR
SHOULD ONLY RESULT IN MINOR SENSIBLE WEATHER ADJUSTMENTS.

.UPPER LEVELS...A LARGE BLOCKING HIGH WAS EVIDENT OVER THE EASTERN
BERING SEA THIS MORNING WITH STRONG NORTHERLY FLOW OVER THE MAINLAND
AND SOUTHERLY SLOW OVER THE WESTERN BERING SEA. THIS HIGH CENTER
MOVES TO NE RUSSIA WED AND THU AS AN EAST TO WEST TROUGH AXIS
DEVELOPS OVER THE GULF AND STRETCHES WEST TO SOUTH OF THE ALEUTIANS.
HEIGHTS WILL CONTINUE TO LOWER OVER THE MAINLAND THROUGH THE WEEKEND
AS A STRONG TROUGH DROPS SOUTH OUT OF THE BEAUFORT SEA AND SETS UP
RESIDENCE OVER THE MAINLAND AND WESTERN GULF LATE SUN. THIS WILL
USHER IN A CHANGE FROM A COLD AND DRY PATTERN TO WETTER AND A
SLIGHTLY WARMER IN THE EAST AND A LITTLE WETTER AND STILL COLD IN THE
WEST EARLY NEXT WEEK.

.SHORT TERM FORECAST...
MAINLAND...HIGH PRESSURE WILL CONTINUE GENERALLY COLD AND DRY
CONDITIONS AROUND THE REGION THROUGH MID TO LATE WEEK. GUSTY GAP
LOWS...ESPECIALLY ACROSS SOUTHCENTRAL ALASKA WILL DIMINISH WED NIGHT
AND THU AS PRESSURE GRADIENTS RELAX SOME WITH WEAKENING MAINLAND
HIGH.

WEAK RETROGRADING (SW MOVEMENT) TROUGH OVER THE GULF OF ALASKA WILL
BRING SNOW TO KODIAK ISLAND TONIGHT. SNOW SHOULD TAPER OFF TO SNOW
SHOWERS LATER WED AS TROUGH CLEARS AREA AND EASTERLY FLOW DIMINISHES.

A WEAKENING FRONTAL TROUGH OVER THE WESTERN ALEUTIANS WILL CONTINUE
WESTWARD PROGRESSION THROUGH TONIGHT. HIGH PRESSURE WITH GENERALLY
EAST OR NORTHEAST FLOW WILL CONTINUE OVER MUCH OF THE BERING SEA OVER
THE NEXT COUPLE OF DAYS. EXPECT CLOUDS AND SNOW SHOWERS OVER THE
EASTERN BERING SEA AS COLD AIR MOVING OFF THE ICE PACK GATHERS
MOISTURE. EXPECT SOME MOISTURE TO CONTINUE TO CLIP THE ALEUTIANS AS
WEAK SYSTEMS TRANSIT TO THE SOUTH OF THE ISLANDS.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...WIND CHILL ADVISORY 155
MARINE...GALE 150 155 170 172 175 176 179 352
FIRE WEATHER...NONE

RMC JAN 12