FXAK68 PAFC 261458
AFDAFC

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
600 AM AKST THU NOV 26 2009

.ANALYSIS AND UPPER LEVELS...
IN THE UPPER-LVLS A BROAD LONG-WAVE TROF REMAINS PREDOMINANT OVER THE
AOR...WITH AN UPPER-LOW OVER JUST SE OF THE PRIBILOF ISLANDS AND OVER
THE NW BERING. A SHORTWAVE TROF IS DRAPED THROUGH THE SUSITNA VALLEY
AND COPPER RIVER BASIN MOVING NORTHEAST. AT THE SURFACE A LOW JUST
NORTH OF DUTCH HARBOR IS FILLING QUICKLY...AND A SMALL LOW IS
DEVELOPING NEAR SAND POINT MOVING EAST. 

.MODEL DISCUSSION...
MODELS ARE BARELY PERFORMING ADEQUATELY IN THE SHORT TERM. THE
WEAKENING LOW SE OF THE PRIBILOFS IS CAPTURED...AS IS THE SHORTWAVE
MOVING UP THE COPPER RIVER BASIN INTO INTERIOR AK. THE LOW NEAR SAND
POINT DID NOT INITIALIZE WELL IN ANY MODEL SOLUTION...AND WAS
EXPECTED TO DEVELOP A BIT FURTHER EAST. REGARDLESS...IT APPEARS THE
SYSTEM WILL MOVE UP TOWARDS NORTHERN KODIAK ISLAND THURSDAY
EVENING...AND UP THE KENAI PENINSULA FRIDAY MORNING. THE NEXT MAJOR
LOW MOVES INTO THE GULF ON SATURDAY...WITH MODELS CAPTURING THIS THE
LAST SEVERAL RUNS REASONABLY CLOSE. OUT WEST ANOTHER STRONG LOW WILL
ADVANCE TOWARDS THE FAR WESTERN ALEUTIANS SATURDAY AFTERNOON...WITH
FAIRLY DECENT MODEL AGREEMENT.

.SHORT TERM FORECAST...
.SOUTHCENTRAL...
SNOW AND RAIN SHOWERS THROUGH PRINCE WILLIAM SOUND BEFORE DEEPER
MOISTURE FROM TRIPLE POINT LOW WORKS UP THURSDAY EVENING. BLIZZARD
CONDITIONS FROM BLOWING SNOW DEVELOPING THROUGH THOMPSON PASS
THURSDAY AFTERNOON AS A STRENGTHENING PRESSURE GRADIENT IN ADVANCE
THE TRIPLE-POINT LOW SET UP STRONG NORTH WINDS OF 30 TO 45 MPH.
FALLING AND BLOWING SNOW WILLS SUSTAIN THE THREAT OF THE BLIZZARD
INTO EARLY FRIDAY MORNING THROUGH THOMPSON PASS...WITH A GENERAL 6 TO
12 INCH SNOWFALL ACROSS EASTERN PRINCE WILLIAM SOUND THROUGH FRIDAY.
EASTERLY TURNAGAIN ARM/PORTAGE VALLEY WINDS IN ADVANCE OF THE LOW
WILL ALSO INCREASE THURSDAY...WITH THE DOWNSLOPING HELPING TO RETARD
PRECIPITATION TO A FEW SNOW SHOWERS THROUGH THE ANCHORAGE BOWL AND
MAT-SU VALLEY DURING THE DAY THURSDAY. THE SUPPORTING UPPER-LVL
SHORTWAVE WILL APPROACH THURSDAY NIGHT AND HELP DRAG SOME LIGHT SNOW
POSSIBLY MIXED WITH RAIN ALONG THE HILLSIDE AND TURNAGAIN ARM. A
GENERAL DRYING TREND DURING THE DAY FRIDAY BEFORE ANOTHER STRONG LOW
MOVES INTO THE GULF OF ALASKA ON SATURDAY.

.SOUTHWEST...
PERIODS OF SNOW ACROSS BRISTOL BAY...THE AKPEN AND INTERIOR KUSKOWIM
VALLEY AS TRIPLE-POINT SYSTEM AND ASSOCIATED UPPER-SUPPORT MOVE NORTH
THROUGH THURSDAY. PRECIPITATION TAPERS TO SHOWERS AND MOVES TO MAINLY
UPSLOPE AREAS OF THE ALEUTIAN/ALASKA RANGE ON FRIDAY. THE LOW MOVING
INTO THE GULF OF AK ON SATURDAY MAY BRUSH THE SOUTHERN AKPEN WITH
SOME BRIEF SNOW EARLY SATURDAY MORNING...OTHERWISE FAIR WEATHER
SETTING UP FOR SW AK THIS WEEKEND...SAVE FOR SHOWERS CONTINUING IN
THE NORTHERLY FLOW ALONG THE AKPEN.

.BERING SEA/ALEUTIANS...
STRONG WINDS DIMINISHING IN THE WAKE OF FILLING LOW PRESSURE SYSTEM
SOUTHEAST OF THE PRIBILOFS...WITH SHOWERS IN THE NORTH-WEST FLOW.
STEADY RAIN AND SNOW WITH STRONG SOUTHERLY FLOW MOVES BACK TO THE
WESTERN ALEUTIANS IN ADVANCE OF ANOTHER DEEP LOW ON SATURDAY.

.LONG TERM FORECAST...
MODELS PERFORMING SATISFACTORILY IN THE MID TO LONG RANGE...SO
FORECAST CONFIDENCE IS FAIR TO GOOD. REMAINING ACTIVE PARTICULARLY
DUE TO A DIGGING LONG WAVE TROF OVER THE EASTERN BERING AND SW AK
DURING THE BULK OF NEXT WEEK.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WARNING...131
MARINE...STORM...170 172
         GALE...351 352 411 412 413 120 125 132 150 155 171 175 176  
                185
HEAVY FREEZING SPRAY...180 185

JAM NOV 09