Heavy Freezing Spray Warning 159, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 PM AKDT TUE APR 10 2012

.ANALYSIS AND UPPER LEVELS...AN UPPER LEVEL RIDGE REMAINS OVER THE
INTERIOR OF THE STATE WHILE AN UPPER LEVEL TROUGH IS OVER THE CENTRAL
BERING SEA WITH A CUT OFF LOW DEVELOPING SOUTH OF THE ALASKA
PENINSULA.A SHARP UPPER LEVEL TROUGH DESCENDS SOUTHWARD OVER THE
KAMCHATKA PENINSULA FROM THE UPPER LEVEL LOW IN EASTERN RUSSIA. THIS
PATTERN IS KEEPING THE JET STREAM RUNNING WELL SOUTH OF THE FORECAST
AREA...THOUGH A POTENT JET STREAK IS FEEDING THE LARGE SURFACE LOW
THAT IS SOUTH OF THE ALASKA PENINSULA. THIS SURFACE LOW IS THE MAIN
WEATHER MAKING FEATURE OVER THE AREA AS SURFACE HIGH PRESSURE IS OVER
THE MAINLAND PART OF THE STATE.
ON THE SMALLER SCALE THERE IS A SERIES OF WEAK SHORT WAVES OVER THE
PANHANDLE THAT ARE MOVING NORTHWEST TOWARD THE COPPER RIVER BASIN.
THESE FEATURES ARE SEEN BEST ON THE IR SATELLITE IMAGERY.

.MODEL DISCUSSION...MODELS CONTINUE TO DO WELL WITH CONSISTENT
SOLUTIONS BETWEEN MODELS AND GOOD RUN TO RUN CONSISTENCY AS WELL. THE
NAM WAS USED FOR DETAILS IN THE EASTERN PART OF THE FORECAST AREA AND
OVER THE MAINLAND AREAS IN THE WESTERN PART OF THE FORECAST AREA.

.SHORT TERM FORECAST...THE LARGE LOW SOUTH OF THE ALASKA PENINSULA IS
THE MAIN WEATHER FEATURE TODAY AND IT IS BRINGING A RAIN AND SNOW MIX
FROM KODIAK ISLAND WESTWARD TO DUTCH HARBOR AND NORTHWARD TO THE
PRIBILOF ISLANDS.
THE SHORT WAVES MOVING TOWARD THE COPPER RIVER BASIN WILL LIKELY NOT
PRODUCE ANY PRECIPITATION AS THE HAVE ONLY BROUGHT SOME MID LEVEL
CLOUDS TO THE PANHANDLE AREA. HOWEVER THE ARE PAVING THE WAY FOR A
FEW MORE WAVES ON THURSDAY THAT COULD BRING SOME PRECIPITATION TO THE
AREA IF ENOUGH MOISTURE BECOMES AVAILABLE.

.LONG TERM FORECAST...THE RIDGE IN THE BERING SEA WILL HOLD FIRM AS A
MODERATE LOW DEVELOPS WELL SOUTH OF THE ALEUTIAN ISLANDS THU AND THEN
MOVES TOWARD THE SOUTHWESTERN GULF THIS WEEKEND. THIS WILL BRING SOME
WINDS TO THE ALASKA PENINSULA THROUGH THE WESTERN GULF OF ALASKA...AS
WELL AS RAIN AND A CHANCE OF SNOW TO COASTAL AREAS THIS WEEKEND.
INTERIOR AREAS OF THE FORECAST AREA WILL REMAIN PARTLY CLOUDY FOR THE
MOST PART WITH EAST TO NORTHEAST FLOW BRINGING IN DRIER AIR.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 132 150 170.
FIRE WEATHER...NONE.

APR 12