Winter Weather Advisory 33, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 AM AKST TUE DEC 11 2012

.ANALYSIS AND UPPER LEVELS...
THERE IS AN UPPER LOW OVER THE FAR WESTERN BERING SEA...AS WELL AS
NEAR THE AK PANHANDLE THIS MORNING...WITH A RIDGE BETWEEN THE TWO. AT
THE SURFACE...A LOW IS MOVING ONSHORE AT THE SOUTHERN
PANHANDLE...WHILE A LOW IS MAKING ITS WAY EASTWARD INTO THE WESTERN
BERING SEA WITH A FRONT STRETCHED ACROSS THE BERING TOWARD BRISTOL
BAY. ANOTHER ROUND OF PRECIPITATION IS MOVING ACROSS THE EASTERN
BERING SEA THIS MORNING HAS REACHED THE SOUTHWEST MAINLAND COAST.
OTHERWISE...THE REGION IS DRY THIS MORNING AS WE HAVE A BRIEF BREAK
IN THE ACTIVE WEATHER.

.MODEL DISCUSSION...
THE MODELS ARE IN GOOD AGREEMENT OVERALL WITH THE SYNOPTIC FEATURES
THROUGH 36 HOURS OR SO...BEFORE DIFFERENCES BECOME GREATER ESPECIALLY
ACROSS THE BERING SEA WITH LOW STRENGTH AND TIMING. THE DIFFERENCES
IN THE FIRST 36 HOURS ARE IMPORTANT HOWEVER...AS SEVERAL AREAS HAVE
THE POTENTIAL TO SEE SNOW CHANGE TO RAIN OR FREEZING RAIN FOR A
PERIOD OF TIME DURING THIS EVENT. THE NAM CONTINUES TO BE THE COLDEST
MODEL. FOR THE AREAS EAST/SOUTH OF THE ALASKA RANGE...THE NAM WAS
PREFERRED FOR WINDS BUT NOT NECESSARILY FOR TEMPERATURES AND
PRECIPITATION TYPE. WEST OF THE ALASKA RANGE...THE GFS IS THE
PREFERRED MODEL THROUGH THE FIRST 84 HOURS.

.SHORT TERM FORECAST...
SOUTH CENTRAL ALASKA...THIS AREA WILL CONTINUE TO SEE A BREAK IN THE
ACTIVE WEATHER FOR MUCH OF THE DAY TODAY...ALTHOUGH PRECIPITATION
WILL BEGIN MOVING EASTWARD AND NORTHWARD ACROSS THE AREA BY THIS
EVENING FOR KODIAK ISLAND AND AT LEAST THE SOUTHERN PART OF THE KENAI
PENINSULA. PRECIPITATION SHOULD BEGIN AS SNOW EVERYWHERE NORTH OF THE
SOUTHERN KENAI PENINSULA. HOW FAR NORTH THE WARM AIR WILL GET WILL
MAKE A BIG DIFFERENCE IN SNOW ACCUMULATIONS...BUT EITHER WAY THERE IS
A SIGNIFICANT AMOUNT OF MOISTURE WITH THIS SYSTEM.

SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...PRECIPITATION WILL GRADUALLY
MOVE INLAND TODAY AS THE LOW MOVES EASTWARD. AS WARM AIR MOVES
NORTHWARD...PRECIPITATION WILL CHANGE FROM SNOW TO FREEZING RAIN
ACROSS THE COASTAL AREAS OF BRISTOL BAY AND THE KUSKOKWIM DELTA.
PRECIPITATION WILL CHANGE TO RAIN ALONG THE ALASKA PENINSULA. THE
FREEZING RAIN ADVISORIES FOR BRISTOL BAY AND THE KUSKOKWIM DELTA
STILL LOOK TO BE ON TRACK SO OTHER THAN STARTING THEM A BIT
EARLIER...WE WILL CONTINUE THEM AS IS.

.LONG TERM FORECAST...
MORE PRECIPITATION CHANCES WILL COME NEXT WEEKEND AS THIS MORE ACTIVE
WEATHER PATTERN CONTINUES. TEMPERATURES WILL GRADUALLY COOL OVERALL
ACROSS THE SOUTHERN MAINLAND DURING THIS TIME.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...STORM WARNING 172 175 176 411 412 413
         GALE WARNING 130 132 150 155 160 165 170 171 179 185 351 352
                      414
         HEAVY FREEZING SPRAY WARNING 185
FIRE WEATHER...NONE

SCHRECK