High Wind in Alaska, December 1, 2010

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKST WED DEC 1 2010

.MODEL DISCUSSION...MODEL INITIALIZATIONS ARE FAIRLY REASONABLE.
MODEL SYNOPTIC FORECAST TRENDS IN AND GENERALLY GOOD AGREEMENT AND
REASONABLE THROUGH THE SHORT TERM (SAT AFTERNOON). BIGGEST CHANGE IN
IN THE LAST THREE MODEL RUNS HAVE BEEN WITH THE ADJUSTMENT OF THE
SURFACE LOW MOVING INTO NEAR THE SW COAST OF ALASKA FRI AND ITS
ASSOCIATED FRONT. MODELS REMAIN CONSISTENT ON TRIPLE POINT
DEVELOPMENT NEAR KODIAK ISLAND FRI MORNING...HOWEVER THERE ARE SOME
DIFFERENCES ON TIMING AND TRACK OF THIS FEATURE INTO SOUTHCENTRAL
ALASKA. THIS CENTER WILL LIKELY MOVE OVER THE KENAI PEN FRI NIGHT.

.UPPER LEVELS...
RIDGING OVER THE EASTERN BERING SEA MOVES EAST TO OVER THE GULF OF
ALASKA AND SOUTHCENTRAL ALASKA LATE TONIGHT THEN TO THE WESTERN GULF
THU AFTERNOON. A TROUGH OVER THE EASTERN BERING SEA TODAY MOVES EAST
AND WEAKENS AS A DEVELOPING CENTER NEAR ITS BASE DRIVES SOUTH INTO
THE NE PACIFIC THU. SO THE TROUGH IS FAIRLY DIFFUSE BY THE TIME IT
MOVES THROUGH THE INTERIOR AND SOUTHCENTRAL ALASKA THU. A STRONG LOW
MOVES ACROSS THE BERING SEA TO NEAR THE SW COAST OF ALASKA FRI AND
SLOWLY WEAKENS AND DRIFTS TO NEAR BRISTOL BAY SAT. A STRONG
SOUTHWESTERLY JET SETS UP OVER THE AK PEN AND SW ALASKA THU EVENING
AND SPREADS OVER SOUTHCENTRAL ALASKA FRI MORNING. BY FRI
EVENING...THE MAIN CORE OF THE JET EXTENDS FROM SOUTH OF THE AK
PEN...OVER THE GULF OF ALASKA...TO THE EASTERN GULF COAST.

.SURFACE SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA
LOCALLY GUSTY WINDS ARE SLOWLY DIMINISHING ACROSS THE NORTH GULF
COAST TODAY AS THE LOW CENTER WEAKENS OVER THE PANHANDLE. ALTHOUGH
PRESSURE GRADIENTS WEAKEN...THERMAL GRADIENTS ASSOCIATED WITH THE
ARCTIC/POLAR AIRMASS OVER THE COPPER RIVER BASIN AND MARITIME AIR
OVER THE GULF WILL REMAIN RELATIVELY STRONG. SO WOULD EXPECT LOCALLY
BRISK GAP WINDS TO CONTINUE OVER THE NORTH GULF THROUGH TONIGHT.
PATCHY FOG WAS OBSERVED ACROSS THE ANCHORAGE BOWL THIS MORNING. IT IS
A GOOD CHANCE THAT IT WILL DEVELOP AGAIN TONIGHT WITH STRONG
INVERSIONS TONIGHT. ON DETRACTOR WILL BE ON HOW MUCH CLOUD COVER
COMES IN WITH APPROACHING WEAK FRONT. FRONT APPROACHING SW ALASKA
TODAY WILL WEAKEN AS IT MOVES ACROSS SOUTHCENTRAL ALASKA THU. CURRENT
THOUGHT IS THAT THE BEST CHANCE OF SNOW WILL BE NEAR KODIAK AND
LESSER AMOUNTS OVER THE THE SOUTHCENTRAL MAINLAND. THE NEXT FRONT
APPROACHING FRI/FRI NIGHT WILL BRING IN THE BEST SHOT OF SIGNIFICANT
SNOWFALL. WINDS AHEAD OF FRONT WILL ALSO PRODUCE STRONG WINDS OVER
THE GULF OF ALASKA AND BRISK GAP WINDS ACROSS SOUTHCENTRAL
ALASKA...ESPECIALLY OVER THE EASTERN KENAI PEN AND ANCHORAGE BOWL.
COULD SEE BLOWING SNOW PROBLEMS OVER THE EASTERN KENAI FRI. TIMING
AND INTENSITY OF THIS POTENTIAL EVENT IS STILL A LITTLE UNCERTAIN AT
THIS POINT. FOR NOW WILL SHOW DETERIORATING TREND IN FORECAST
CONDITIONS

WESTERN ALASKA.
FRONT APPROACHING SW ALASKA THIS AFTERNOON ACROSS THE AREA LATE
TONIGHT. SO SNOW SHOULD GIVE WAY TO A FEW BREAKS AND SNOW SHOWERS
LATE TONIGHT AND THU. A LOW CENTER OVER THE WESTERN BERING SEA LATE
TONIGHT MOVES TO NEAR NUNIVAK ISLAND FRI MORNING THEN WEAKENS OVER
THE SW INTERIOR FRI NIGHT. A SECONDARY LOW CENTER THEN MOVES TO OVER
BRISTOL BAY EARLY SAT. THE ASSOCIATED FRONT MOVES TO NEAR THE EASTERN
ALEUTIANS AND PRIBILOF ISLANDS LATE FRI MORNING THEN TO THE SW
MAINLAND THU EVENING. THE FRONT THEN MOVES INTO SOUTHCENTRAL ALASKA
ON FRI. MODELS DIFFER SOME ON THE AMOUNT OF WARM ADVECTION AHEAD OF
FRONT INTO SW ALASKA THU NIGHT. THE GFS SEEMS TO BE THE MOST
AGGRESSIVE AND WOULD SUGGEST MIXED RAIN AND IN BRISTOL BAY COASTAL
LOCATIONS AND SNOW OVER MUCH OF THE REMAINDER OF SW ALASKA. STRONG
WINDS ARE EXPECTED WITH AND AHEAD OF THE APPROACHING FRONT SO BLOWING
SNOW IS ALSO LIKELY OVER INLAND BRISTOL BAY AND OVER MUCH OF THE
DELTA. MAY EVEN SEE A FEW POCKETS OF FREEZING RAIN INTO BRISTOL BAY
THU NIGHT. SINCE MODELS HAVE UNDERGONE A SIGNIFICANT SHIFT...WILL
TREND FORECAST CONDITIONS DOWN AND WAIT FOR ANOTHER RUN BEFORE
CONSIDERING WWA.

.LONG TERM FORECAST...AS GULF/N PACIFIC LOW STALLS LATE SAT/SUN
A WAVE MAY MOVE N ALONG FRONT AND DEVELOP A LOW OVER EASTERN GULF
COAST THEN AND BRING ANOTHER SHOT OF RAIN/SNOW TO OUTER COAST
SUN...AND KENAI LATE SUN/MON. WHICH WOULD THEN MOVE TOWARD PADQ...BY
LATE MON. N TO NE SURFACE PRESSURE GRADIENTS WILL TIGHTEN UP OVER
S-CENTRAL AND COPPER BASIN SUN/MON...RETURNING GUSTY OFFSHORE FLOW.
SW AK AND MOST OF ALEUTIANS TO REMAIN UNDER COOL NORTHERLY FLOW
THEN...WITH SOME SCATTERED -SHSN POSSIBLE FROM ABOUT PADU EAST.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE....STORMS 176 175. GALES 150 155 170 172.
FIRE WEATHER...NONE.

RMC DEC 10