Heavy Freezing Spray Warning 65, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
352 PM AKST FRI FEB 18 2011

.ANALYSIS AND UPPER LEVELS...
AN ACTIVE WEATHER PATTERN PERSISTS ACROSS ALASKA...BRINGING SEVERAL
STORM SYSTEMS TO THE AREA. WITH UPPER LEVEL RIDGING OVER SOUTHEAST
ALASKA...AND UPPER LEVEL TROUGHING OVER THE BERING SEA...SOUTH
CENTRAL REMAINS IN BETWEEN WITH SOUTHWEST FLOW ALOFT. THIS PATTERN
WILL SHIFT EAST OVER THE NEXT COUPLE DAYS...PUTTING THE TROUGH OVER
SOUTHEAST ALASKA AND ZONAL FLOW ACROSS THE BERING AND SOUTHWEST
ALASKA BY SUNDAY.

.MODEL DISCUSSION...
MODELS ARE IN GOOD AGREEMENT TODAY...SHOWING GENERALLY THE SAME IDEA
AS FAR AS HOW FAST PRECIPITATION WILL MOVE OUT OF SOUTH CENTRAL
ALASKA FOR THE EARLY PART OF THE WEEKEND AND THE ZONAL FLOW OVER THE
BERING SEA AND WESTERN ALASKA BY THE END OF THE WEEKEND.

.SHORT TERM FORECAST...
SNOW HAS BEEN FALLING OVER MUCH OF SOUTH CENTRAL ALASKA THROUGH THE
DAY TODAY...ESPECIALLY ANCHORAGE EAST. THE MAIN CONCERN FOR TONIGHT
INTO SATURDAY IS SNOWFALL AMOUNTS IN THE COPPER RIVER BASIN THROUGH
SATURDAY AS THE SURFACE LOW PASSES BY TO THE SOUTH. ANOTHER SURFACE
LOW WILL MOVE INTO SOUTHWEST ALASKA BY THE END OF THE WEEKEND...BUT
IT DOES NOT LOOK TO PACK THE SAME PUNCH THAT THE LAST ONE DID FOR
THAT AREA.

PRECIPITATION IS EXPECTED TO CONTINUE FROM THE EASTERN KENAI
PENINSULA THROUGH SUSITNA VALLEY AND EASTWARD TO CORDOVA THROUGH THE
NIGHT. AROUND ANCHORAGE...VERY LIGHT SNOW OR FREEZING DRIZZLE IS
EXPECTED...WITH SOUNDINGS SHOWING A BIT OF DRYING IN THE MID-LAYERS
TONIGHT THAT COULD MEAN NOT ENOUGH CLOUD ICE AVAILABLE FOR SNOW.
MOISTURE WILL CONTINUE TO BE SQUEEZED OUT OF THE RELATIVELY THIN
CLOUD DECK THAT IS OVER THE AREA.

SNOWFALL AMOUNTS HAVE BEEN INCREASED ACROSS THE COPPER RIVER
BASIN...WITH THAT AREA BEING IN THE FAVORABLE NORTHWEST QUADRANT IN
RELATION TO THE DEVELOPING/STRENGTHENING SURFACE LOW NEAR MIDDLETON
ISLAND TO GET SOME DECENT SNOWFALL. TOTALS ARE EXPECTED TO REMAIN
BELOW ADVISORY LIMITS. THE TIME OF HEAVIEST SNOWFALL FOR THIS AREA
WILL BE TONIGHT THROUGH LATE SATURDAY MORNING.

.SOUTHWEST ALASKA AND BERING SEA...STRATUS AND SNOW SHOWERS WILL
CONTINUE ACROSS SOUTHWEST ALASKA THROUGH SATURDAY. THE NEXT SURFACE
LOW WILL BE FAST MOVING...AND WILL BRING SOME SNOW TO MUCH OF
SOUTHWEST ALASKA ON SUNDAY. SOME STRONGER WINDS WILL ACCOMPANY THIS
LOW...WITH THE STRONGEST WINDS BEING STORM FORCE OVER THE WESTERN
BERING ON SATURDAY. THE LOW WILL GRADUALLY WEAKEN AS IT MOVES INTO
NORTHWEST ALASKA...THEREFORE THE SURFACE WINDS ASSOCIATED WITH THE
LOW WILL WEAKEN AS WELL.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...STORM WARNING...176 185 411 412 .
         GALE WARNING...120 129 130 132 150 165 170 172 175 179 180
                        351 352 413 414.
         HEAVY FREEZING SPRAY WARNING...185.
FIRE WEATHER...NONE

MBS