Snow Advisory 4, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AST SAT NOV 25 2006

.DISCUSSION...

PERSISTENT UPPER LEVEL RIDGE OVER WESTERN ALASKA WITH CUT-OFF LOWS
OVER THE WESTERN BERING AND SE AK THIS MORNING. AT THE SURFACE...HIGH
PRESSURE IS CENTERED OVER MAINLAND AK WITH A DISSIPATING FRONT/TROUGH
ALONG WESTERN AK EXTENDING ACROSS THE AKPEN AND KODIAK ISLAND INTO
THE GULF. A LOW IS OVER THE WESTERN BERING AND A RAPIDLY MOVING
SHORTWAVE IS APPROACHING THE EASTERN AND CENTRAL ALEUTIANS.

MODELS ARE IN AGREEMENT THAT THE UPPER RIDGE AXIS WILL MIGRATE TO THE
ALCAN BY MON. THE MAIN PLAYER IN THE SHORT TERM IS THE SHORTWAVE
HEADED TOWARD THE CENTRAL ALEUTIANS. THIS WILL BRING ABUNDANT
MOISTURE TO WESTERN ALASKA ALONG WITH SIGNIFICANT WINDS. FOR THE
MORNING FORECAST THE GFS REMAINS THE MODEL OF CHOICE EXCEPT AFTER 72
HOURS IN THE WESTERN BERING WHERE CONFIDENCE BECOMES LOW.

EAST OF THE AK RANGE...CLOUDS FROM THE DECAYING FRONT WILL AFFECT
KODIAK AND THE KENAI TODAY...WITH SOME LOW CLOUDS FROM THE GULF
AFFECTING THE NORTH GULF COAST. OTHERWISE HIGH PRESSURE WILL KEEP
COLD AND DRY CONDITIONS OVER THE AREA INTO SUN. THE SECOND FRONT...
ASSOCIATED WITH THE SHORTWAVE IN THE BERING...WILL BRING SNOW TO
KODIAK ISLAND ON SUN...WHICH WILL SPREAD ACROSS THE COAST BY SUN
NIGHT. SHOWERY PRECIP WILL SPREAD INLAND MON AND TUE.

WEST OF THE AK AND ALEUTIAN RANGES...HIGH PRESSURE INLAND WILL KEEP
CLOUDS AND A FEW SHOWERS ALONG THE COAST TODAY. AS THE SHORTWAVE
CROSSES THE ALEUTIANS TONIGHT...WIND WILL INCREASE ALONG THE COAST
WITH LIGHT SNOW DEVELOPING. ON SUN...WIND COMBINED WITH SNOW MAY
PRODUCE BLIZZARD CONDITIONS OVER THE KUSKOKWIM DELTA THAT PERSISTS
INTO MON. SNOW WILL ALSO AFFECT THE REST OF THE AREA...DIMINISHING
MON AND ENDING TUE.

FOR THE ALEUTIANS AND BERING...RAIN...GALES AND STORMS WILL AFFECT
EASTERN PORTIONS THIS AFTERNOON THROUGH EARLY SUN. SMALL CRAFT OR
WEAKER WINDS WILL THEN BLOW ACROSS THE AREA INTO TUE. FOR WESTERN
PORTIONS...EXCEPT FOR SOME SMALL CRAFT WINDS TODAY...BENIGN
CONDITIONS WILL PREVAIL UNTIL GALES BRIEFLY DEVELOP SUN NIGHT.
SOMETIME ON TUE THE NEXT KAMCHATKA LOW WILL BEGIN TO BRING GALES AND
POSSIBLE STORMS TO THE WESTERN ISLANDS...BUT THE EXACT TIMING OF THE
ARRIVAL OF THAT SYSTEM IS CURRENTLY UNCERTAIN.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WATCH 155
MARINE...HEAVY FREEZING SPRAY 140 141 180 185
         GALES 130 132 138 150 155 160 165 171
         STORMS 170 172 179 180 185
FIRE WEATHER...NONE

DS NOV 06