Heavy Freezing Spray Warning 55, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
532 AM AKST MON MAR 7 2016

.ANALYSIS AND UPPER LEVELS...
THE MAIN UPPER LEVEL LOW THAT WAS OVER THE BERING HAS PUSHED SOUTH
OF THE CENTRAL ALEUTIANS AS IT WEAKENS. ANOTHER LOW SITS SOUTH OF
THE PANHANDLE AND THESE TWO LOWS HAVE ALLOWED FOR WARM SOUTHEAST
FLOW TO MOVE OVER SOUTHCENTRAL ALASKA. OUT WEST...HIGH PRESSURE
REMAINS BRINGING COLD NORTHERLY WINDS TO MUCH OF THE BERING.

&&

.MODEL DISCUSSION...
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE MID TERM WITH THE
MAJOR FEATURES. THIS RESULTS IN ABOVE AVERAGE CONFIDENCE.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...
A WEAK SURFACE TROUGH SETTING UP FROM PRINCE WILLIAM SOUND INTO THE
KENAI PENINSULA WILL BRING GUSTY WINDS TO THE GULF COAST AND
SOUTHERN COOK INLET TODAY...AND THEN RAPIDLY DIMINISH AS THE
TROUGH DISSIPATES OVER THE COAST. A WEAK UPPER LEVEL TROUGH MOVING
NORTHWARD TOWARDS THE NORTH GULF COAST WILL BRING RAIN/SNOW TO THE
GULF COAST TODAY...AND MAY EVEN SPREAD A FEW RAIN/SNOW SHOWERS
INTO INTERIOR SOUTHCENTRAL BY LATE TONIGHT. THIS WILL HOWEVER BE A
RELATIVELY QUICK MOVING SYSTEM WITH WEAK DYNAMICS...SO AT THIS
POINT WE DO NOT EXPECT WIDESPREAD ACCUMULATING SNOW TO THE AREA
FOR TUESDAY MORNING. SKIES SHOULD THEN CLEAR THROUGHOUT
SOUTHCENTRAL BY TUESDAY AFTERNOON AS WEAK RIDGING MOVES INTO THE
AREA...WITH THE GULF COAST EXPERIENCING CONTINUED CLOUD COVER AND
RAIN/SNOW THROUGHOUT THE DAY. AFTERWARDS THE MODELS HAVE BACKED
OFF SIGNIFICANTLY SINCE YESTERDAY WITH THE POTENTIAL FOR AN
EASTERLY WAVE MOVING OVER SOUTHCENTRAL LATE TUESDAY-WEDNESDAY. AS
A RESULT IT NOW APPEARS THAT THIS PRECIPITATION WILL REMAIN
CONFINED TO THE GULF COAST INTO WEDNESDAY.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
A WEAK SURFACE TROUGH EXTENDING FROM THE WESTERN GULF INTO
BRISTOL BAY WILL FOCUS LIGHT SNOW ALONG THE COAST BETWEEN
DILLINGHAM AND KING SALMON THROUGH THIS AFTERNOON AS AN UPPER
LEVEL DISTURBANCE MOVES OVERHEAD...WITH RAIN BEGINNING TO MIX IN
LATER IN THE DAY AS TEMPERATURES GRADUALLY CLIMB ABOVE FREEZING.
SCATTERED SHOWER ACTIVITY WILL LINGER OVER THE BRISTOL BAY REGION
THROUGH TUESDAY AS THE SURFACE LOW GRADUALLY WEAKENS AND AN UPPER
TROUGH LIFTS NORTHWARD THROUGH THE AREA. A PERIOD OF DRIER
CONDITIONS WILL BEGIN TO TAKE HOLD ON TUESDAY NIGHT AS HIGH
PRESSURE BUILDS OVER THE SOUTHERN MAINLAND FROM THE EAST...
YIELDING INCREASING OFFSHORE FLOW ALONG THE SOUTHWEST COAST.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
A NUMBER OF DISTINCT FEATURES WILL COMBINE TO PRODUCE WIDESPREAD
SHOWERY CONDITIONS ACROSS THE BERING THROUGH TUESDAY. SNOW
SHOWERS WILL DECREASE IN COVERAGE THROUGH THIS AFTERNOON ACROSS
THE EASTERN ALEUTIANS AS THE NORTH PACIFIC LOW ANCHORED NEARBY
BEGINS TO MOVE OFF TO THE SOUTH AND EAST...HOWEVER MORE NUMEROUS
SNOW SHOWERS WILL CONTINUE TO ENCOMPASS THE CENTRAL BERING
IN PERSISTENT NORTHERLY FLOW ON THE BACKSIDE OF THE LOW.
MEANWHILE...A WEAK FRONTAL BOUNDARY WILL MOVE OVER THE WESTERN
ALEUTIANS THIS EVENING AND BRING LIGHT SNOW TO THOSE AREAS THROUGH
TUESDAY AFTERNOON. A MUCH STRONGER FRONT WILL FOLLOW CLOSELY ON
TUESDAY NIGHT ACCOMPANIED BY GALE FORCE WINDS AND POTENTIALLY
HEAVIER PRECIPITATION.

&&

.LONG TERM FORECAST (DAYS 4 THROUGH 7)...

BY WEDNESDAY EVENING...THERE WILL BE A BROAD LOW IN THE SOUTHERN
GULF OF ALASKA...WITH A DEEPENING NEAR STORM FORCE LOW MOVING
ACROSS THE BERING SEA. WEAKENING ENERGETIC WAVES WRAPPING AROUND
THE PARENT GULF LOW WILL BE SPREADING SOME MOISTURE ALONG THE
COAST...BUT MOST IF NOT ALL PRECIP WILL STAY THERE WITH DRY INLAND
CONDITIONS. THE LONE DISCREPANCY WILL BE ACROSS SOUTHWEST ALASKA
WEST OF THE ALASKA RANGE WHERE SOME MOISTURE MAY INTERACT
FAVORABLY WITH A MID LEVEL SHORTWAVE TROUGH TO PRODUCE SOME
SCATTERED SHOWER ACTIVITY. OTHERWISE...THE BERING TROUGH AND
ASSOCIATED POLAR JET WILL DIVE SOUTHEAST AND MERGE WITH THE GULF
LOW...SENDING MOST OF THE JET ENERGY WELL SOUTH OF THE
REGION...AND KEEPING MOST OF INLAND ALASKA DISPLACED FROM THE
STORM TRACK.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE 352
         HEAVY FREEZING SPRAY 185 412

&&

SYNOPSIS AND MODEL DISCUSSION...DK
SOUTHCENTRAL ALASKA...DEK
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...CB
LONG TERM...JA