Snow Advisory 8, NWS Anchorage, AK

AREA FORECAST DISCUSSION...UPDATED
SOUTH CENTRAL AND SOUTHWEST ALASKA
320 PM AST WED DEC 13 2006

UPDATED WARNING LIST

.DISCUSSION...
ALOFT.  A WEAK UPPER TROUGH EXTENDING FROM ANADYR THROUGH KODIAK
ISLAND WILL MOVE SLOWLY EASTWARD TO EXTEND FROM THE BERING STRAIT
THROUGH SOUTHERN COOK INLET BY THURSDAY MORNING THEN TO NORTHERN COOK
INLET BY THURSDAY NIGHT.  A TRANSIENT RIDGE WILL MOVE ACROSS THE
BERING AND ONSHORE ALONG THE WEST COAST BY FRIDAY MORNING. AN UPPER
LOW WILL FORM OVER THE EXTREME WESTERN BERING BY THURSDAY MORNING AND
MOVE TO 120 MILES SOUTHWEST OF ANADYR BY FRIDAY AFTERNOON.

SURFACE.  A WEAK LOW NEAR MIDDLETON ISLAND WILL PERSIST THROUGH
THURSDAY NIGHT.  A LOW IN THE SOUTHWEST BERING WILL DEEPEN AND MOVE
TO THE NORTHWEST BERING BY LATE THURSDAY AND TO THE NORTH CENTRAL
BERING BY LATE FRIDAY. A MODERATELY STRONG FRONT OVER THE WESTERN
BERING WILL MOVE TO THE CENTRAL BERING AND ADAK BY THURSDAY AFTERNOON
AND THEN ONSHORE ALONG THE SOUTHWEST ALASKA COAST AND BRISTOL BAY BY
LATE FRIDAY.

WEATHER.  EXPECT AREAS OF LIGHT SNOW FOR SOUTH CENTRAL LATER TONIGHT
AND THURSDAY WITH THE UPPER TROUGH MOVING IN FROM THE WEST. NORTH TO
WEST WINDS GUSTING TO 35 MPH OVER PRINCE WILLIAM SOUND AND CHANNELED
AREAS ON THE WESTERN NORTH GULF COAST TONIGHT THROUGH FRIDAY. THESE
WINDS ARE DUE TO A TIGHT GRADIENT THAT BUILDS BETWEEN THE STATIONARY
MIDDLETON ISLAND LOW AND A RIDGE MOVING OVER THE SOUTHWEST COAST.
STRONG WINDS RAIN AND SNOW WILL MOVE ACROSS THE ALEUTIANS AND BERING
WITH THE FRONT. LIGHT SNOW ASSOCIATED WITH A WEAK FRONT OVER THE
EASTERN ALEUTIANS AND ALASKA PENINSULA WILL END TONIGHT.

MODELS.  THE MAIN DIFFERENCE IS BETWEEN THE NAM AND GFS190 WITH THE
MIDDLETON ISLAND LOW.  THE NAM IS THE PREFERRED SOLUTION KEEPING THE
LOW NEAR MIDDLETON ISLAND THROUGH THURSDAY.  THE GFS IS TOO QUICK IN
MOVING THE LOW EAST.  THE UKMET AGREES WITH THE NAM SOLUTION.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...GALE  130 132 150 155 165 172 175 176 185 350 410
         HEAVY FREEZING SPRAY 121 130 138 140 160 180 185

RHH DEC 06