Gale Warning 238, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AST THU MAR 02 2006

.DISCUSSION...

SATELLITE IMAGERY SHOWS MAJOR FEATURE BEING LARGE COLD FRONTAL BAND
STRETCHING ACROSS MUCH OF WESTERN ALASKA THAT STEMS FROM WEAKENING
SURFACE LOW IN THE ANADYR GULF. SURFACE OBS INDICATE THAT WINDS ALONG
THE SOUTHWEST AK COAST HAVE SUBSIDED WITH THE FRONTAL PASSAGE WHILE
THE FRONT HAS YET TO MAKE IT THROUGH BETHEL...WHERE WINDS ARE STILL
SOUTH WITH VISIBILITIES AROUND 1 MILE. THE STANDATD COLD AIR STRATOCU
ARE BEING OBSERVED BEHIND THE FRONT ACROSS THE BERING SEA WITH SNOW
SHOWERS EMBEDDED IN THE WEST NORTHWEST FLOW. HIGH CLOUDS AHEAD OF THE
FRONT HAVE SPREAD ACROSS MUCH OF SOUTHCENTRAL OVERNIGHT...ALLOWING
TEMPERATURES TO STAY A FEW DEGREES WARMER OVERNIGHT THAN THE PREVIOUS
NIGHT.

IN THE UPPER LEVELS THE PRIMARY FEATURE IS THE ANCHOR LOW CENTERED
OVER THE NORTHWESTERN BERING SEA/ANADYR GULF WITH A SHORTWAVE TROUGH
EXTENDING SOUTH INTO THE EASTERN ALEUTIANS. TO THE EAST A RIDGE
EXTENDS ACROSS THE GULF OF ALASKA AND ACROSS THE MIDDLE OF THE STATE
TO THE ARCTIC.

UPPER LEVEL...MODELS ARE IN GOOD AGREEMENT OVER THE NEXT FEW DAYS.
SPLIT FLOW PATTERN DEVELOPS IN THE UPPER LEVELS AROUND RIDGING IN
NORTHERN CANADA. THE TROUGH OVER THE EASTERN BERING DIGS SOUTH TODAY
BEFORE THE MAIN ENERGY BREAKS AWAY FROM THE ANCHOR LOW IN THE
NORTHWEST BERING AND IS SHUNTED SOUTHEAST AND AWAY FROM AK BY THE
250MB JET ON FRI. THE REMAINING TROUGH STILL ATTACHED TO THE ANCHOR
LOW ROTATES ACROSS SOUTHWEST AND SOUTHCENTRAL AK SAT AHEAD OF THE
NEXT MAJOR SYSTEM. THIS UPPER LOW MOVES RAPIDLY ACROSS THE BERING SEA
ON FRI BEFORE MOVING ASHORE OVER SOUTHWEST AK ON SAT EVENING AND
WEAKENING AS JET SUPPORT IS LOST. THE UPPER LOW ELONGATES OUT INTO A
NEGATIVELY TILTED TROUGH ACROSS SOUTHCENTRAL SUNDAY AS AN UPPER
TROUGH MOVES ACROSS THE CENTRAL ALEUTIANS.

SURFACE...SURFACE LOW DEVELOPS OVER AKPEN BY THIS EVENING AND MOVES
SOUTH WITH THE UPPER LOW AS IT DEPARTS AK WITH THE JET STREAM. WITH
MOST OF THE ENERGY BEING SITUATED WELL SOUTH OF SOUTHCENTRAL AK...IT
APPEARS THAT THE MAIN PRECIP POTENTIAL WILL BE FLURRIES IN THE
ANCHORAGE BOWL/MATSU VALLEY IN ASSOCIATION WITH WRAPAROUND MOISTURE
AROUND THE SURFACE LOW. THE KENAI AND WESTERN PRINCE WILLIAM SOUND
ZONES HAVE A BETTER SHOT AT RECEIVING SNOW AS THEY ARE CLOSER TO THE
LOW AS WELL AS ONSHORE RETURN FLOW AND LIMITED OVERUNNING. THE NEXT
BIG WEATHER MAKER IS THE WARM FRONTAL BAND THAT PUSHES ACROSS THE
WESTERN AND CENTRAL ALEUTIANS TODAY AND INTO FRI AS A LARGE
DEVELOPING LOW MOVES INTO THE CENTRAL BERING. LOOK FOR STORM FORCE
WINDS TO MOVE ACROSS THE BERING ON FRI IN THE COLD AIR ADVECTION
BEHIND THE LOW. LOOK FOR PRECIP TO SPREAD ACROSS MUCH OF THE FORECAST
AREA THROUGH THE WEEKEND AS THIS LOW MAKES LANDFALL OVER SOUTHWEST AK
SAT NIGHT.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...GALE 150 155 170 172 175 179 185
         STORM 176
         HEAVY FREEZING SPRAY 130 140
FIRE WEATHER...NONE

WOOD FEB 06