000
FXAK68 PAFC 052330
AFDAFC
AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM AKST MON JAN 5 2009
.MODEL DISCUSSION...MODELS ARE CONVERGING ON A COMMON SOLUTION AS THE
BLOCK SHIFTS EAST. THE 12Z GFS/ECMWF ARE IN FAIRLY GOOD AGREEMENT
THROUGH 96 HRS. THIS AFTERNOON FORECAST IN GENERAL WILL BE BASED ON
THE 12Z GFS MODEL.
.UPPER LEVELS...BLOCKING PATTERN IS FORECAST TO SHIFT EAST. UPPER LOW
OVER THE GULF MOVES INTO WESTERN CANADA TUE AND INTO THE CENTRAL
CANADIAN PROVIDENCES FRI. LOW COMPLEX SOUTH OF THE ALEUTIANS SHIFTS
NORTH AND EAST TO OVER THE EASTERN BERING SEA/AK PEN FRI NIGHT. SW
FLOW SETS UP OVER THE GULF AS RIDGE SHIFTS TO THE EASTERN
GULF/MAINLAND THU EVENING. THE STORM TRACK WILL LIKELY SHIFT NORTH
WITH THE ONSET OF SW FLOW ALOFT AND ALLOW LOW CENTERS AND MOISTURE TO
PENETRATE FURTHER INTO THE SOUTHERN MAINLAND AND GULF.
.SHORT TERM FORECAST...
.EAST...MAINLAND RIDGE WITH GULF LOW PATTERN WILL WEAKEN OVER THE
NEXT DAY OR SO. BRISK GAP/GRADIENT FLOWS WILL WEAKEN OVER
SOUTHCENTRAL TONIGHT AND ALONG THE NORTH GULF TUE. TEMPERATURES
SHOULD HOLD RELATIVELY STEADY WITH NEUTRAL TEMPERATURE
ADVECTION...THOUGH WILL SEE COOLER TEMPS IN PREVIOUSLY WINDY AREAS.
TEMPERATURES SHOULD WARM OVER MUCH OF THE GULF AND SOUTHCENTRAL
ALASKA WED NIGHT AND THU AS LOW CENTER HEADS TOWARD THE WESTERN GULF.
THIS CENTER WILL ALSO BRING MOISTURE WITH A CHANCE OF SNOW TO MUCH OF
THE NORTHERN GULF BY THU AFTERNOON.
.SW ALASKA...
.LONG TERM FORECAST...OFFSHORE FLOW AND COLD TEMPS WILL CONTINUE OVER
THE SW MAINLAND THROUGH WED. TEMPS WILL WARM AND WINDS WILL INCREASE
ACROSS THE AK PEN AND SW ALASKA AS A WEATHER FRONT ASSOCIATED WITH
DEVELOPING LOW SOUTH OF THE ALEUTIANS MOVES OVER THE AK PEN WED NIGHT
AND BRISTOL BAY THU.
.ALEUTIANS/BERING SEA...STRONG EASTERLY WINDS ARE EVIDENT OVER MUCH
OF THE BERING SEA AND CENTRAL AND WESTERN ALEUTIANS TODAY. WINDS ARE
EXPECTED TO STRENGTHEN AND BACK NORTH TO NORTHEAST AS A DEVELOPING
STORM CENTER MOVES SOUTH OF THE EASTERN ALEUTIANS WED. WINDS LOOK
FAIRLY STRONG OVER THE CENTRAL ALEUTIANS ON THE BACKSIDE OF FRONTAL
TROUGH WED NIGHT. WINDS COMBINED WITH SNOW COULD PRODUCE BLIZZARD
POTENTIAL OVER THE CENTRAL ALEUTIANS WED NIGHT AND THU.
.LONG TERM FORECAST...A POSSIBLE BREAK FROM THE WELL BELOW NORMAL
TEMPERATURES MAY BE IN THE NEAR FUTURE. THE WEATHER PATTERN WILL BE
TRENDING TOWARDS MULTIPLE LOWS MOVING FROM THE NORTH PACIFIC INTO THE
GULF. THE FIRST LOW THAT WILL MOVE INTO THE GULF TOWARDS THE WEEKEND
WILL WARM UP COASTAL AREAS...BUT IT MAY NOT BE UNTIL THE SECOND OR
THIRD LOW ENTERS THE GULF THAT THE WARMER INFLUENCE IS FELT FURTHER
INLAND.
.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...WIND WARNING 135.
MARINE...GALE WARNING...176
FIRE WEATHER...NONE.
RMC JAN 09
