Gale Warning 901, NWS Anchorage, AK

SOUTH CENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
300 PM AKST MON NOV 22 2010

.MODEL DISCUSSION...MODELS REMAIN IN GOOD AGREEMENT ON PRIMARY
SURFACE FEATURES THROUGH WED NIGHT. THE GFS TRACKS THE EASTERN
ALEUTIAN LOW A BIT FARTHER NORTH THAN THE OTHER NUMERICAL MODELS.  WE
PREFER THE MORE SOUTHERLY TRACK BRINGING THIS LOW TO THE ALEUTIANS
THEN TURNING IT EAST INTO THE GULF CROSSING OVER KODIAK ISLAND.  ON A
SMALLER SCALE THE NAM WAS MUCH BETTER THAN THE GFS WITH THE FREEZING
RAIN OVER SOUTH CENTRAL THIS MORNING.  THE GFS KEPT THE PRECIPITATION
EAST OF ANCHORAGE AND PALMER.

.ANALYSIS AND UPPER LEVELS...A HIGH AMPLITUDE RIDGE ALONG 150W WILL
MOVE SLOWLY EASTWARD TO SOUTHEAST ALASKA BY TUE NIGHT AND CONTINUE
MOVING EAST THEREAFTER. A LOW PRESSURE TROUGH OVER THE CENTRAL BERING
SEA WILL MOVE TO EXTEND FROM NORTHWEST ALASKA TO THE CENTRAL GULF OF
ALASKA BY LATE WED. WARM MOIST AIR WILL CONTINUE TO MOVE FROM THE
SOUTH OVER MOST OF SOUTHERN ALASKA THROUGH TUE IN ADVANCE OF THE
TROUGH. IN LOW LYING AREAS IN THE SUSITNA VALLEY...THE MATANUSKA
VALLEY AND IN EAST ANCHORAGE BELOW FREEZING AIR SHOULD PERSIST MAKING
FREEZING RAIN LIKELY WITH THE NEXT WAVE OF PRECIPITATION EXPECTED TO
MOVE OVER THE AREA TONIGHT.

.SHORT TERM FORECAST...
SOUTHWEST...RAIN OVER MOST OF THE REGION TONIGHT AND TUESDAY. COOLING
WILL BEGIN FROM THE WEST WITH RAIN CHANGING TO SNOW STARING LATE TUE
ALONG THE SOUTHWEST COAST AND MOVE OVER BRISTOL BAY WED.

SOUTH CENTRAL...THE NEXT BAND OF PRECIPITATION IS EXPECTED TO MOVE
OVER THE AREA TONIGHT AND TUESDAY.  FREEZING RAIN IS EXPECTED IN THE
SUSITNA VALLEY....THE MATANUSKA VALLEY AND IN EAST ANCHORAGE. RAIN IS
LIKELY ELSEWHERE EXCEPT SNOW AT HIGHER ELEVATIONS IN THE ALASKA
RANGE.

.LONG TERM FORECAST...
SOUTHWEST...COOLER AND DRYER AIR THU AND FRI WITH A CHANCE OF SNOW
SAT WITH A WEAK LOW MOVING IN FROM THE BERING.

SOUTH CENTRAL...COOLER THU THROUGH SUNDAY WITH A SLIGHT CHANCE OF
SNOW THU.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...ICE STORM WARNING 111 AND 145
MARINE...GALE 150 155 165 170 180 171 172 179
FIRE WEATHER...NONE

RHH NOV 10

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ANCHORAGE AK
1215 PM AKST MON NOV 22 2010

AKZ101-111-145-230000-

...SIGNIFICANT ICE ACCUMULATION AROUND SOUTH CENTRAL ALASKA...

AREAS OF FREEZING RAIN CONTINUE AROUND SOUTH CENTRAL ALASKA THIS
AFTERNOON. TEMPERATURES AT THE SURFACE REMAIN BELOW FREEZING WHILE
TEMPERATURES ALOFT REMAIN MUCH WARMER. RAIN THAT IS FALLING IS
FREEZING ON CONTACT AND CAUSING HAZARDOUS DRIVING CONDITIONS.

PRECIPITATION HAS TAPERED OFF IN ANCHORAGE AND IS EXPECTED TO TAPER
OFF LATER THIS AFTERNOON ACROSS THE MATANUSKA VALLEY. THE SUSITNA
VALLEY WILL SEE A MUCH LONGER SUSTAINED PERIOD OF PRECIPITATION
THROUGH TUESDAY.

TEMPERATURES WILL GRADUALLY WARM LATER TONIGHT AS THE NEXT BATCH OF
MOISTURE ARRIVES ACROSS SOUTH CENTRAL ALASKA. THE POTENTIAL FOR
ANOTHER FREEZING RAIN EVENT IS POSSIBLE AGAIN TONIGHT THROUGH
TUESDAY MORNING.

NOV 10