Gale Warning 909, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM AST SAT DEC 1 2007

.MODEL DISCUSSION...12Z GFS RUN IS CLOSING IN ON THE ECMWF LATEST
RUN. THE MOST NOTABLE IS THE TIMING AND INTENSITY OF NEXT LOW
ENTERING THE BERING SEA MON NIGHT AND TUE. SO WILL LEAN TOWARD THE
NEW GFS OUT WEST TO ACCOUNT FOR DEEPER AND FASTER MOVEMENT.

.ANALYSIS AND UPPER LEVELS...
.EAST...BLOCKING UPPER HIGH OVER THE MAINLAND IS EVIDENT ON THE
AFTERNOON IR SAT PICTURE. MORNING SOUNDINGS FROM PAFA...PANC...AND
PAYA SHOW THAT THE 300 MB JET WAS A LITTLE OVER DONE ON EARLIER MODEL
PROJECTIONS. UPPER JET SHOULD INTENSIFY SOME AS FORECAST AND SHIFT
OVER THE CENTRAL AND WESTERN MAINLAND TONIGHT AND SUN AS UPPER HIGH
MOVES TO THE ARCTIC OCEAN AND LOW MOVES INTO THE EASTERN GULF.
GENERALLY COLD TEMPS WERE OBSERVED OVER THE EASTERN MAINLAND AND
WESTERN CANADA OVERNIGHT WITH CLEARING. NE FLOW AROUND UPPER HIGH
SPREADS COLD AIR ACROSS MAINLAND ALASKA STARTING TODAY AND CONTINUING
THROUGH MON. THE WARMER AIR SPREADS TO THE SOUTHERN MAINLAND TUE AND
WED AS THE FLOW SHIFTS TO THE SOUTH. PRESSURE/TEMPERATURE GRADIENTS
INCREASE ACROSS THE REGION TODAY AND CONTINUE FAIRLY STRONG INTO MON.
EXPECT COMBINATION OF STRONG TEMP/PRESSURE GRADIENTS COMBINED WITH
UPPER JET SUPPORT WILL PRODUCE HIGH WIND WARNING CONDITIONS FOR ZONES
131 AND 135 TONIGHT AND SUN AND 111 SUN. WIND WARNING CONDITIONS
SHOULD DIMINISH OVER THESE AREAS MON AS UPPER FLOW WEAKENS AND SHIFTS
EASTERLY. ELSEWHERE...LOCALIZED STRONG GAP AND ENHANCED DRAINAGE
WINDS LIKELY THROUGH MON NIGHT. LOCALIZED WIND CHILL CONDITIONS WILL
ALSO BE A CONCERN THROUGH MON.

.WEST...OLD FRONTAL BOUNDARY IS CONTINUING TO WEAKEN AND WILL SHIFT
WSW AND DISSIPATE WITH ONSET OF NE UPPER FLOW. DRY AND COLDER AIR
LIKELY OVER THE WESTERN MAINLAND WITH SOME LOCALLY GUSTY WINDS
THROUGH MON. EXPECT CLOUDS WITH A CHANCE OF SNOW TO SPREAD TO SW
ALASKA MON NIGHT/TUE AS A LOW PRESSURE TROUGH PUSHES INTO THE EASTERN
BERING SEA/BRISTOL BAY. DEVELOPING STORM OVER THE NORTH PACIFIC IS
FORECAST TO MOVE TO THE WESTERN ALEUTIANS TUE EVENING AND TO THE
EASTERN BERING SEA ON WED EVENING. THIS TRACK IS FASTER ON THE 12Z
RUN OF THE GFS AND IS IN GOOD AGREEMENT WITH THE ECMWF TREND.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...UPGRADE HIGH WIND WATCHES TO WARNINGS FOR ZONES 101 111 AND
         135.
MARINE...GALES 120 129 130 132 138 140 150 155 160 165 170 AND 172.
FIRE WEATHER...NONE.

RMC DEC 07