Ice Storm in Alaska, October 30, 2007

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM ADT TUE OCT 30 2007

.MODEL DISCUSSION...MODELS INITIALIZATIONS REASONABLE AS WELL AS
GENERAL FORCAST TRACKS THROUGH FRI AFTERNOON. HOWEVER...INTENSITY AND
PRESSURE OF CENTER MOVING SOUTH OF THE ALEUTIANS/AK PEN TO THE WEST
GULF OF ALASKA WED NIGHT WILL MOST LIKELY UNDERGO SOME ADJUSTMENTS.
GFS HAS BEEN FAIRLY CONSISTENT AND WILL GO THAT WAY WITH SOME SHORT
TERM ADJUSTMENTS FOR THIS FORECAST PACKAGE.

.ANALYSIS....

.EAST...THE MAIN FEATURE IN THE EAST IS THE 960S LOW OVER THE BARREN
ISLANDS. SAT/OBS DATA INDICATES THAT THE CENTER IS SLOWLY MOVING N.
12Z MODELS ARE TAKING CENTER MORE UP COOK INLET...BUT FEEL N TRACK
MAY BE A LITTLE SLOWER AND POSSIBLY LITTLE FURTHER EAST. THIS HAS
CAUSED SOME CONCERN FOR WIND WARNINGS FOR ZONES 101 AND 125. PRESSURE
SURGE ON BACKSIDE OF FRONT HAS INCREASED WINDS TO JUST BELOW WARNING
LEVELS IN 125...HOWEVER WINDS HAVE NOT QUITE COME UP OVER THE WESTERN
END OF TURNAGAIN ARM AFTER INITIAL PRE-FRONTAL SURGE. EXPECT THAT AS
THE AFTERNOON CONTINUES AND LOW MOVES SLOWLY N THAT WINDS MAY
INCREASE AGAIN TO NEAR WARNING LEVELS FOR ZONE 101 AND DIMINISH AGAIN
TONIGHT AS THE LOW CENTER MOVES OVER THE SUSITNA VALLEY. EXPECT
CENTER MAY MOVE A LITTLE SLOWER THEN CURRENT FORECAST...SO WOULD HOLD
UP THE WINDS OVER MUCH OF SOUTHCENTRAL/GULF THIS EVENING. WIND SHOULD
BE SHIFTING TO THE SOUTH OVER THE COPPER RIVER LATE THIS AFTERNOON
WITH WILL REMAIN BRISK THROUGH TONIGHT. EXPECT RAIN BECOMING MIXED
WITH SNOW OVER MUCH OF SOUTHCENTRAL TONIGHT WITH WEAK COLD ADVECTION
ON THE BACK SIDE. MAY SEE A COUPLE OF INCHES OVER HIGHER ELEVATIONS
OF 101 125 AND 141. NEXT LOW MOVING TO THE WESTERN GULF WED NIGHT/THU
WILL BRING ANOTHER BATCH OF WARM AIR AND WINDS.

.WEST...UPPER TROUGH OVER THE SW AK HOLDS.  SURFACE LOW FROM OVER IN
WESTERN INTERIOR AND DRIFTS SOUTHWEST TO OVER THE DELTA WED AFTERNOON
AND EVENTUALLY TO OVER BRISTOL BAY THU. SNOW WILL CONTINUE/SPREAD
OVER MUCH OF THE SW MAINLAND THROUGH TONIGHT. HIGHER SNOW AMOUNTS
EXPECTED ALONG THE ALEUTIAN RANGE WITH SW UPSLOPE FLOW. SNOW SHOULD
DIMINISH OVER BRISTOL BAY WED. MOST PREDOMINATE AREAS FOR SNOW LIKELY
OVER THE DELTA AS SURFACE LOW DROPS OVER THE AREA. STRONG NW WINDS
OVER THE EASTERN BERING SEA/AK PEN WILL DIMINISH THROUGH THE NIGHT AS
THE LOW OVER SOUTHCENTRAL MOVES NORTH AND WEAKENS. EXPECT NW WINDS TO
INCREASE AGAIN OVER THE ALEUTIANS WED AFTERNOON AND SPREAD TO THE
EASTERN BERING SEA/AK PEN WED NIGHT/THU AS LOW UNDERCUTS THE AK PEN.

HIGH SURF CONDITIONS WITH SPRING TIDES AND WIND/WAVE CONDITIONS WILL
BRIEFLY PRODUCE A 2-4 FT SURGE ABOVE MAT THIS EVENING MUCH OF SW AK.
EXPECT EVENT TO BE OVER AFTER MIDNIGHT TONIGHT.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...HIGH WIND WARNING 101 AND 125 DIMINISHING. HIGH SURF
ADVISORY THIS EVENING 155 AND 161.
MARINE...SHORT TERM ADJUSTMENT WILL BE NECESSARY. SEE CURRENT LIST.

RMC OCT 07