High Wind Watch 14, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM AKST SUN NOV 30 2008

.MODEL DISCUSSION...MODELS IN GENERAL INITIALIZED WELL ON THE
SYNOPTIC SCALE FEATURES THOUGH THE ECMWF DID A BETTER JOB ON INITIAL
CONDITIONS WITH LOW COMPLEX SOUTH OF THE ALEUTIANS. FORECAST MODEL
TRENDS ARE REASONABLE AND IN FAIR AGREEMENT THROUGH ABOUT 60 HOURS.
DIFFERENCES CROP UP SOUTH OF THE GULF OF ALASKA AFTER THAT AND ISSUES
DEVELOP WITH THE HANDLING OF THE LOW COMPLEX SOUTH OF THE ALEUTIANS.
BOTH THE GFS40 AND ECMWF CARRY A STRONG LOW SOUTH OF THE ALEUTIANS
WITH THE ECMWF A LITTLE FURTHER WEST OF THE GFS40 WED AFTERNOON. THIS
DISCONTINUITY BECOMES MORE PRONOUNCED BEYOND THIS POINT WITH
THE ECMWF CONTINUING FURTHER WEST. ALTHOUGH THE ECMWF LOOKS MORE
REASONABLE...WILL NOT MAKE ANY CHANGES AT THIS POINT TO THE EXTENDED
GRIDS.

.UPPER LEVELS...NEGATIVELY TILTED TROUGH EXTENDING FROM A LOW CENTER
OVER THE SEWARD PENINSULA THROUGH THE SOUTHERN GULF OF ALASKA IS
ROTATING SLOWLY EASTWARD. SATELLITE IMAGERY SHOWS WARMING CLOUD TOPS
TEMPERATURES OVER PORTIONS OF SOUTHCENTRAL ALASKA. THE TROUGH SHOULD
CLEAR SOUTHCENTRAL THIS EVENING AND MOVES INTO THE INTERIOR AND
WESTERN CANADA MON. LOW CENTER OVER THE SEWARD PENINSULA MOVES SLOWLY
ALONG THE BROOKS RANGE AND SETS UP STRONG WESTERLY ZONAL FLOW OVER
THE SOUTHERN MAINLAND STARTING LATE TONIGHT AND CONTINUING THROUGH
EARLY TUESDAY. BROAD CUT-OFF LOW COMPLEX SOUTH OF THE ALEUTIANS
UNDERGOES SOME CHANGE...HOWEVER THERE IS LITTLE OVERALL MOVEMENT OF
THE SYSTEM THROUGH WED MORNING. THE GFS TENDS TO BE THE MOST
PROGRESSIVE IN PUSHING THE CENTER NORTH...ECMWF MAY HAVE A BETTER
HANDLE BY HOLDING THE LOW COMPLEX WEST.

.SHORT TERM FORECAST...
.EAST...WEAKENING LOW IS MOVING SLOWLY EAST ACROSS PRINCE WILLIAM
SOUND. COLD ADVECTION HAS MOVED INTO SOUTHCENTRAL ALASKA AND
CONVERGENT BANDS OF SNOW CONTINUE OVER NORTHERN COOK INLET. WE THE
EXCEPTION OF A BRIEF ENHANCEMENT OF SNOW AS THE UPPER TROUGH MOVES
THROUGH SOUTHCENTRAL. THE SNOW SHOULD DIMINISH THROUGH THIS
EVENING...HOWEVER WILL LINGER THROUGH THE LATE NIGHT IN THE COPPER
RIVER BASIN. COLD ADVECTION WITH STRONG GAP FLOWS OVER COOK INLET AND
NORTH GULF ARE EVIDENT ON THE SAT IMAGERY AND NEXRAD RADARS. EXPECT
GAP FLOWS TO INTENSIFY THROUGH TONIGHT AS HIGH PRESSURE BUILDS OVER
THE MAINLAND AND A WEAK INVERTED TROUGH CONTINUES OVER THE GULF OF
ALASKA. THESE CONDITIONS LIKELY WILL CONTINUE INTO WED. SHOULD SEE
DRYING AS RIDGE BUILDS OVER THE MAINLAND THROUGH MON. MOISTURE MOVES
INTO SOUTHCENTRAL/NORTH GULF WITH FRONTAL TROUGH TUE AND WED.

.WEST...
LOW COMPLEX SOUTH OF THE ALEUTIANS WILL HOLD ITS GENERAL POSITION
OVER THE NEXT DAY OR SO. THE MAIN 960S CENTER SOUTH OF THE ALEUTIANS
WILL EVENTUALLY WEAKEN AS A SECONDARY FEATURE DEVELOPS UNDER A STRONG
NORTH PACIFIC JET AND MOVES INTO THE BASE OF THE TROUGH. THIS FEATURE
WILL LIKELY REPLACE THE CURRENT LOW AS IT DEEPENS INTO THE 960S TUE.
STRONG WINDS LIKELY TO HOLD OVER MUCH OF THE ALEUTIANS AND AK PEN
OVER THE NEXT DAY OR SO AS THESE LOWS SHIFT PLACES. HIGH WIND
POTENTIAL EXISTS FOR THE WESTERN ALEUTIANS MON AS LOW SOUTH OF THE
ALEUTIANS RETROGRADES WEST. TEMPS IN GENERAL SHOULD BE TOO WARM FOR
BLIZZARD CONDITIONS OVER THE ALEUTIANS/AK PEN. CURRENT PLAN IS TO
CANCEL THE BLIZZARD WATCH FOR THE PRIBILOFS. ALTHOUGH THE WINDS WILL
INCREASE...THE FRONT IS NOT LIKELY TO MAKE MUCH HEADWAY NORTH AND
TEMPS MAY REMAIN TOO WARM. EXPECT COLD TEMPS OVER THE SOUTHWEST
MAINLAND THROUGH MON NIGHT. TEMPS WILL MODERATE SOME IN BRISTOL BAY
AS MOISTURE MOVES INTO THE AREA.

.LONG TERM FORECAST...
THE STRONG AND NEARLY STATIONARY LOW SOUTH OF THE ALEUTIANS WILL BE
THE MAJOR WEATHER FEATURE INTO THE MIDDLE OF NEXT WEEK. HIGH PRESSURE
BUILDING OVER THE MAINLAND WILL REMAIN INTO THE MIDDLE OF WEEK WHEN
THE LOW SOUTH OF THE ALEUTIANS FINALLY MOVES INTO THE GULF OF ALASKA.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WATCH 195 WILL BE CANCELED. POTENTIAL HIGH WIND
WATCH
         ZONE 187.

MARINE...STORMS 130 170 172 175 176.
         GALES  121 129 132 138 150 155 165 171 179 180 185.

RMC NOV 08