Blizzard in Alaska, December 17 to 18, 2008

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
300 PM AKST WED DEC 17 2008

.MODEL DISCUSSION...MODELS ARE IN GOOD AGREEMENT WITH EACH OTHER
THROUGH 60 HOURS. THE BIGGEST CONCERN IS THAT THE SOLUTION CONTINUES
TO CHANGE WITH THE RUNS SO THE MODEL CONSISTENCY IS NOT WHAT ONE
WOULD HOPE FOR. THE OVERALL TREND HAD BEEN TO BREAK DOWN THE RIDGE IN
THE BERING SEA FRIDAY THROUGH SATURDAY NIGHT. PREVIOUS RUNS HAD IT
STRONGLY POSITIONED IN THE CENTRAL TO EASTERN BERING SEA AT THAT
TIME. THE SUCCESSIVE RUNS ON THE GFS HAVE BEEN FORCING IT FARTHER TO
THE SOUTH. OF THE MAJOR MODELS THE ECMWF LOOKS TO BE THE MOST
CONSISTENT.

.ANALYSIS AND UPPER LEVELS...THE UPPER LEVEL PATTERN HAS A WARM RIDGE
EXTENDING FROM THE GULF OF ALASKA THROUGH THE CENTRAL PART OF THE
STATE TO THE ARCTIC COAST. THE RIDGE WILL TRY TO HOLD FAST BUT WILL
BE PUSHED EASTWARD BY FRIDAY. IN THE WEST THERE IS A CUT OFF UPPER
LEVEL LOW OVER THE CENTRAL ALEUTIANS THAT WILL MOVE EASTWARD OVER THE
NEXT FEW DAYS. HIGH PRESSURE WILL BUILD IN AGAIN BEHIND THIS LOW BUT
THE RIDGE WILL NOT BE AS STRONG AS PREVIOUSLY THOUGHT. THE JET STREAM
WILL REMAIN SOUTH OF THE AREA THROUGH THE WEEKEND.

THE SURFACE LOW IN THE CENTRAL ALEUTIANS WILL SLOWLY MOVE
SOUTHEASTWARD THROUGH FRIDAY BRINGING IN COLDER AIR TO THE EASTERN
ALEUTIANS AND EVENTUALLY THE ALASKA PENINSULA. HIGH PRESSURE WILL
REDEVELOP IN THE INTERIOR OF THE STATE AND HELP PUSH THIS LOW SOUTH
OF THE AREA RELEGATING MOST OF THE PRECIPITATION WITH IT TO THE
COASTAL AREAS AS IT MOVES INTO THE GULF OF ALASKA.

.SHORT TERM FORECAST...RAIN WILL CONTINUE TO BE THE DOMINANT FORM OF
PRECIPITATION IN THE BRISTOL BAY REGION UNTIL THURSDAY NIGHT. THERE
IS USUALLY CONCERN ABOUT FREEZING RAIN IN THE DILLINGHAM AREA WITH
THIS SORT OF PATTERN BUT THE POTENTIAL LOOKS WEAK AT THIS TIME. THE
WINDS IN DILLINGHAM REMAINED NORTH ALL NIGHT AND THE TEMPERATURE
REMAINED ABOVE FREEZING SO THERE IS EVIDENTLY NOT A SIGNIFICANT
AMOUNT OF COLD AIR AVAILABLE TO PRODUCE FREEZING RAIN. FREEZING RAIN
IS A POSSIBILITY IN THE SOUTHERN PORTION OF THE KUSKOKWIM VALLEY AS
THERE IS COLDER AIR AT THE SURFACE.
THE WARM AIR IS FIRMLY OVER THE EASTERN BERING SEA REGION WITH
TEMPERATURES IN THE MID TO UPPER 30S STRETCHING FROM BRISTOL BAY TO
THE PRIBILOF ISLANDS AND NORTH PAST NUNIVAK ISLAND.

BLIZZARD CONDITIONS ARE EXPECTED TO DEVELOP THIS EVENING IN THE
CENTRAL ALEUTIANS. THE LOW IN THE CENTRAL ALEUTIANS WILL MOVE SLOWLY
SOUTHEASTWARD AND BRING SNOW AND BLOWING SNOW IN THE COLD ADVECTION
AND STRONG WINDS ON ITS WEST SIDE.

FOG IN THE NORTHERN COOK INLET REGION SHOULD DIMINISH AS MID LEVEL
CLOUDS MOVE INTO THE AREA OVERNIGHT.

.LONG TERM FORECAST...MILD AND PROGRESSIVE WESTERLY FLOW APPEARS TO
SET UP FOR THE WEEKEND AND EARLY NEXT WEEK.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD 187.
MARINE...GALE 130 170 171 175 176.
         STORM 172.
FIRE WEATHER...NONE.

DEC 08