Small Craft Advisory 147, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM AKST THU FEB 12 2009

.MODEL DISCUSSION...MODELS INITIALIZED WELL AND SHORT TERM TRENDS ARE
REASONABLE.

.UPPER LEVELS...PROGRESSIVE PATTERN CONTINUES. BROAD LOW OVER THE
ARCTIC OCEAN GENERALLY HOLDS POSITION OVER THE NEXT COUPLE OF DAYS.
TROUGH FROM THIS SYSTEM DIGS SW ACROSS EASTERN RUSSIA TO JAPAN. SHORT
WAVES MOVING ACROSS ASIA ROUND THE BASE OF THE TROUGH AND MOVE
RAPIDLY ACROSS THE NORTH PACIFIC THROUGH THE WEEKEND.

.SHORT TERM FORECAST...
.EAST...WEAK TROUGH MOVING ACROSS SOUTHCENTRAL THIS AFTERNOON WILL
KEEP A CHANCE OF SNOW IN THE COPPER RIVER BASIN THROUGH THE EARLY
EVENING HOURS. A MODERATE WEATHER FRONT MOVING OVER THE ALAKSA
PENINSULA THIS EVENING MOVES TO OVER THE WESTERN GULF AND KODIAK
ISLAND SAT MORNING. THE FRONT SHOULD STALL AND SLOWLY WEAKEN SAT
AFTERNOON AS RIDGE BUILDS OVER THE COPPER RIVER BASIN AND NORTH GULF
COAST. EXPECT THE MAJORITY OF PRECITATION(RAN/SNOW) TO HOLD OVER THE
WESTERN GULF...MAY SEE SOME LIGHT SNOW SPREADING INTO THE KENAI PEN
ON SAT. PRESSURE GRADIENTS SHOULD BUILD ACROSS SOUTHCENTRAL TONIGHT
WITH APPROACH OF FRONTAL TROUGH. SO WILL SEE LOCALLY STRONG WINDS
THROUGH GAPS TONIGHT AND FRI. WINDS SHOULD DIMINISH FRI NIGHT...BUT
INCREASE AGAIN SUN AS NEXT STORM ENTERS THE BERING SEA.

.WEST...
FRONTAL TROUGH APPROACHING SW ALASKA COAST THIS MORNING IS PRODUCING
BLIZZARD CONDITIONS ACROSS ZONE 155. CONDITIONS SHOULD IMPROVE FRI AS
WINDS DIMINISH OVERNIGHT. OLD STORM SYSTEM NEAR THE WESTERN ALEUTIANS
IS STACKED WITH UPPER CENTER AND MOVES SOUTH OF THE AK PEN AND
WEAKENS FRI. COLD ADVECTION AND STRONG WINDS ON THE BACK SIDE OF THIS
CENTER ARE PRODUCING BLIZZARD CONDITIONS OVER THE WESTERN ALEUTIANS
THIS AFTERNOON. BLIZZARD WILL SPREAD TO THE CENTRAL ALEUTIANS THIS
EVENING. SECONDARY LOW MOVING INTO THE EAST/CENTRAL BERING SEA THIS
AFTERNOON BECOMES THE DOMINATE CENTER AS IT MOVES TO NEAR SAINT
MATTHEW ISLAND THIS EVENING. THIS CENTER WEAKENS AS IT ENTERS WESTERN
NORTON SOUND FRI EVENING. YET ANOTHER STORM CENTER MOVES TO NEAR ADAK
SAT AFTERNOON. THIS CENTER HOLDS IN THE 970S AS IT WINDS TO THE
EASTERN BERING SEA SUN AFTERNOON.

.LONG TERM FORECAST...THE OVERALL PATTERN WILL CONTINUE TO BE QUITE
ACTIVE ACROSS THE DOMAIN THROUGH THE WEEKEND AND BEYOND...BUT
SPECIFICS REMAIN UNRESOLVED AS ALL GUIDANCE DIVERGES BEYOND
TUESDAY...AND MODEL RUNS CONTINUE TO FLIP-FLOP.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WARNING 191 AND 155. WINTER STORM WARNING 187.
MARINE...HURRICANE FORCE WIND WARNING...172
         STORM WARNING...170 175 176 185
         GALE WARNING...130 132 138 140 150 160 165
                        180 181
FIRE WEATHER...NONE.

RMC FEB 09