Heavy Freezing Spray Warning 59, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKST MON JAN 30 2012

.MODEL DISCUSSION...
MODELS INITIALIZED WELL ON THE SYNOPTIC SCALE. THE ECMWF AND NAM
APPEAR TO BE THE MOST REASONABLE WITH THE NEXT STORM CENTER TO ENTER
THE SOUTHERN GULF OF ALASKA WED NIGHT. THE GFS LOOKS TO BE TOO FAST.
SO AFTERNOON PACKAGES IN THE EAST WILL BE A BLEND OF THE ECMWF/NAM
WHILE GRIDS WILL BE TRENDED TOWARD THE GFS IN THE WEST.

UPPER LEVELS...SHORT WAVES EMBEDDED IN THE SOUTHWESTERLY FLOW MOVE
ACROSS THE SOUTHERN MAINLAND OVERNIGHT. A SHORT WAVE MOVING ACROSS
THE NORTH PACIFIC INTENSIFIES AS IT COMES IN PHASE WITH A TROUGH
OVER THE SOUTHERN BERING SEA. COLD AIR ASSOCIATED WITH THE BERING SEA
TROUGH WILL PUSH SOUTH AND DIG OUT NORTH PACIFIC TROUGH WED. THIS IN
TURN AMPLIFIES THE RIDGE OVER THE NORTH GULF COAST AND TUE NIGHT/WED.

.SHORT TERM FORECAST...
.SOUTHCENTRAL...
SHORT WAVES MOVING ACROSS SOUTHCENTRAL ALASKA AND A WEAK INVERTED
SURFACE TROUGH WILL CONTINUE THE THREAT OF SNOW THROUGH TONIGHT. THE
MORE SIGNIFICANT OF THE WAVES MOVES OVER THE SUSITNA VALLEY/COOK
INLET LATE TONIGHT THEN RAPIDLY EAST ON TUE. SNOW SHOULD TAPER OFF
FROM THE WEST TUE.

THE NEXT SIGNIFICANT LOW TO ENTER THE SOUTHERN GULF OF WED WILL BRING
UNSETTLED WEATHER AND BECOME A SOURCE OF NUMEROUS
WATCH...WARNINGS...AND ADVISORIES. THE LOW DEVELOPS UNDER A DIGGING
UPPER TROUGH AND INTENSE JET AND MOVES OUT OF THE NORTH PACIFIC TO
SOUTH OF KODIAK ISLAND WITH A PRESSURE IN THE 950S WED NIGHT. THIS
LOW THEN MOVES TO THE NORTHERN GULF THU AFTERNOON AND WEAKENS INTO
THE 960S. THE ASSOCIATED FRONTAL TROUGH MOVES TO THE SOUTHERN GULF OF
ALASKA WED MORNING AND TO THE NORTH GULF COAST WED NIGHT. EXPECT GALE
TO STORM FORCE WINDS AHEAD OF FRONT AS IT PUSHES NORTH. PRECIPITATION
ASSOCIATED WITH FRONT WILL START AS SNOW THEN GRADUALLY BECOME MIXED
WITH RAIN ALONG COASTAL AREAS. THERE MAY BE A PERIOD OF OF BLIZZARD
CONDITIONS NEAR KODIAK ISLAND AND SOME NORTH GULF LOCATIONS BEFORE
TEMPERATURES WARM SIGNIFICANTLY. INLAND AREAS OF SOUTHCENTRAL EXCEPT
FOR THE WESTERN SUSITNA VALLEY SHOULD EXPERIENCE DOWNSLOPE CONDITIONS
WITH INCREASING SOUTHEAST FLOW ALOFT.

.SOUTHWEST ALASKA...
GENERALLY NORTHERLY FLOW AND COLD TEMPERATURES WILL CONTINUE ACROSS
THE REGION...LOW WIND CHILLS ARE EXPECTED INTO THU ACROSS THE DELTA.
WIND CHILLS SHOULD NOT BE AS SIGNIFICANT OVER THE BRISTOL BAY ZONE
WITH WARMER AMBIENT TEMPERATURES. INCREASING WINDS ARE EXPECTED
ACROSS THE DELTA/BRISTOL BAY WED AND THU WITH A STORM CENTER
APPROACHING THE GULF. STRONG INVERSIONS OVER THE KUSKOKWIM VALLEY
WILL KEEP WINDS ALOFT. THE FRONT ASSOCIATED WITH THE LOW APPROACHING
THE GULF MAY PUSH SOME MOISTURE INTO BRISTOL BAY WED NIGHT.

.ALEUTIANS/BERING SEA/AK PEN...
THE LOW COMPLEX OVER THE ALEUTIANS/BERING SEA MOVES SOUTHEAST OF THE
ALEUTIANS TUE AND WEAKENS. SNOW AND WIND ON THE BACKSIDE OF THE
COMPLEX WILL BRING A PERIOD OF BLIZZARD CONDITIONS THE THE CENTRAL
ALEUTIANS. WINDS AND SNOW WILL INCREASE ACROSS THE AK PEN WED/WED
NIGHT AS A STORM CENTER APPROACHES THE GULF. WEAK RIDING BUILDS OVER
THE WESTERN ALEUTIANS TUE MORNING AND THE CENTRAL ALEUTIANS TUE
NIGHT. WEAK LOW PRESSURE MOVES TO THE WESTERN ALEUTIANS TUE NIGHT.

.LONG TERM FORECAST...
INCREASINGLY AMPLIFIED PATTERN BEGINS TO TAKE SHAPE WITH RAPIDLY
STRENGTHENING LOW OVER THE NORTH PACIFIC BY WEDNESDAY WHICH MOVES
NORTH TOWARDS THE GULF COAST THURSDAY. WITH INCREASINGLY STRONG
SOUTHERLY FLOW WE SHOULD EXPECT TEMPERATURES AT LEAST NEAR NORMAL AND
PRECIPITATION ABOVE NORMAL BY LATE THIS WEEK INTO THE WEEKEND OVER
SOUTHCENTRAL ALASKA.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WARNING 187.
MARINE...GALES 132 150 155 172 175
FIRE WEATHER...NONE.

RMC JAN 12