FXAK68 PAFC 271410
AFDAFC
AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AKST FRI NOV 27 2009
.ANALYSIS AND UPPER LEVELS...
UPPER LEVEL TROUGH EXTENDS FROM EASTERN RUSSIA TO EASTERN AK THIS
MORNING WITH EMBEDDED LOWS OVER THE SOUTHERN BERING AND THE AKPEN. AN
UPPER RIDGE IS OVER SOUTHEAST AK. AT THE SURFACE...SMALL BUT VIGOROUS
LOWS ARE OVER THE NORTHEASTERN GULF AND THE SOUTHERN BERING...WITH A
STRONGER LOW NEAR THE BARREN ISLANDS. THESE SYSTEMS ARE ASSOCIATED
WITH GALE FORCE WINDS OVER THE GULF AND BERING...AND SNOW AND BLOWING
SNOW NEAR BRISTOL BAY. A RIDGE OF HIGH PRESSURE LIES EAST OF THE
PANHANDLE.
.MODEL DISCUSSION...
MODELS HAVE ALL COME INTO AGREEMENT OVER THE NEXT FEW DAYS. THE LOW
OVER THE BARRENS WILL MOVE INLAND TODAY INTO THE SUSITNA VALLEY AND
BEYOND. THE LOW OVER THE NORTHEASTERN GULF WILL MOVE INLAND WEST OF
YAKUTAT TODAY. THE SOUTHERN BERING LOW WILL DISSIPATE THIS EVENING
OVER THE CENTRAL ALEUTIANS. A LOW CURRENTLY WELL SOUTH OF THE EASTERN
ALEUTIANS WILL BE THE NEXT IMPORTANT FEATURE. THIS LOW WILL MOVE
RAPIDLY TO THE NORTHEASTERN GULF SAT NIGHT AND SLOWLY DISSIPATE
THROUGH SUN. THE FINAL PLAYER IN THE SHORT TERM IS A LOW CURRENTLY
OVER NORTHERN JAPAN WHICH WILL INTENSIFY AS IT MOVES TO THE CENTRAL
BERING BY SUN NIGHT...PINWHEELS AROUND THE BERING THROUGH TUE NIGHT
AND THEN REACHES THE BERING STRAIT THU MORNING. THE FORECAST UTILIZES
THE NAM IN THE SHORT TERM FOR DETAIL AND THEN THE GFS/EC THROUGH THE
MID RANGE.
.SHORT TERM FORECAST...
IN THE WEST...RAIN AND SNOW SHOWERS WILL SLOWLY DIMINISH TODAY AS
WEAK HIGH PRESSURE BUILDS. THE LOW AND ASSOCIATED FRONT COMING FROM
NORTHERN JAPAN SPREADS RAIN AND STORM FORCE WINDS ACROSS THE BERING
AND ALEUTIANS SAT AFTERNOON THROUGH MON...AND THEN SNOW SHOWERS WILL
FOLLOW THE LOW WITH STORM FORCE WINDS THROUGH TUE.
FOR SOUTHWEST AK...DRYING TODAY AS THE LOW MOVES INTO THE SUSITNA AND
PRECIPITATION CUTS OFF EARLY OVER THE AKPEN. WEAK RIDGING WILL GIVE
WAY TO SNOW SHOWERS CHANGING TO RAIN AS THE JAPAN FRONT AND LOW MOVE
ACROSS THE BERING. THESE CONDITIONS WILL SLOWLY IMPROVE BY TUE.
SOUTH AND EAST OF THE AK RANGE...AS THE BARREN ISLAND LOW MOVES
INLAND EXPECT RAIN ON THE COAST WITH LIGHT AMOUNTS OF SNOW MOVING
INLAND TODAY. SOME DRYING WILL OCCUR UNTIL THE NEXT LOW MOVES TO THE
NORTHERN GULF COAST SAT. RAIN WILL PRECEDE THIS FEATURE FOR COASTAL
AREAS WITH LITTLE PRECIP CROSSING THE MOUNTAINS. RESIDUAL LOW
PRESSURE FORMS SUN NEAR PRINCE WILLIAM SOUND THAT MAY SEND SNOW INTO
THE SOUTH CENTRAL. A RIDGE WILL DRY OUT THE AREA MONDAY.
.LONG TERM FORECAST...
A SLOW DRYING TREND IS EXPECTED OVER THE BERING WITH A WEAK RIDGE.
THIS WILL ALSO AFFECT THE SOUTHWEST. SOUTHEAST OF THE AK RANGE WILL
HAVE RAIN AND SNOW FROM ANOTHER WEATHER FRONT PERSISTING THROUGH
MID-WEEK.
.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...STORMS 120 130 132
GALES 125 129 150 155 175 176
HEAVY FREEZING SPRAY...180 185
FIRE WEATHER...NONE
DS NOV 09