Small Craft Advisory 195, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 PM AKST SAT MAR 2 2013

.ANALYSIS AND UPPER LEVELS...
THE MAIN FEATURE OF INTEREST THIS AFTERNOON IS THE 980 MB LOW
CURRENTLY PASSING APPROXIMATELY 150 MILES SOUTH OF THE EASTERN
ALEUTIANS AS IT CONTINUES TO TRACK EASTWARD AND GRADUALLY WEAKEN. AN
ASSOCIATED FRONT EXTENDS NORTHWARD FROM THE LOW TO NEAR THE PRIBILOF
ISLANDS AND THEN CURVES SOUTHEASTWARD THROUGH THE EASTERN BERING AND
ACROSS THE CENTRAL AKPEN...WITH AREAS OF SNOW ONGOING OVER THESE
LOCATIONS. THE BLIZZARD WARNING FOR THE PRIBILOFS HAS BEEN ALLOWED TO
EXPIRE...HOWEVER GUSTY WINDS WILL ALLOW AREAS OF BLOWING SNOW TO
PERSIST INTO THE EVENING HOURS. BLIZZARD CONDITIONS HAVE ALSO
SUBSIDED OVER THE CENTRAL ALEUTIANS...ALTHOUGH STRONG NORTHWESTERLY
WINDS ON THE BACKSIDE OF THE LOW CONTINUE TO SUPPORT BLOWING SNOW
OVER THESE AREAS AS WELL. A NEGATIVELY TILTED UPPER LEVEL RIDGE OVER
THE SOUTHWEST MAINLAND EXTENDS INTO THE WESTERN GULF OF
ALASKA...YIELDING CALM CONDITIONS ACROSS MUCH OF THE SOUTHERN
MAINLAND.

.MODEL DISCUSSION...
MODELS ARE IN REASONABLE AGREEMENT THROUGH THE SHORT TERM WITH
RESPECT TO THE OVERALL SYNOPTIC PATTERN. THE LOW SOUTH OF THE
ALEUTIANS WILL CONTINUE TO WEAKEN AND BEGIN TO MOVE SOUTHEASTWARD
INTO THE NORTHEAST PACIFIC TONIGHT AS IT ENCOUNTERS THE UPPER RIDGE
IN PLACE OVER THE MAINLAND. THE RIDGE WILL SLIDE EASTWARD ON SUNDAY
AND TRANSITION TO A CLOSED UPPER HIGH AS IT IS UNDERCUT BY THE
AFORMENTIONED LOW...REMAINING IN PLACE OVER SOUTHCENTRAL AK THROUGH
THE EARLY PART OF THE WEEK. MODELS DIFFER SOMEWHAT IN THE PLACEMENT
OF THE FRONT POISED TO MOVE INTO THE WESTERN GULF THIS EVENING...WITH
THE EC BRINGING THE FRONT CLOSER TO THE CENTRAL GULF BY SUNDAY
AFTERNOON WHEREAS THE GFS/NAM SOLUTIONS KEEP IT FURTHER WEST IN THE
VICINITY OF KODIAK ISLAND. DESPITE THESE DIFFERENCES...ALL MODELS
DEPICT THE FRONT STALLING OVER THE GULF AND WEAKENING AS IT
ENCOUNTERS THE RIDGE. CONTINUED TO UTILIZE THE GFS FOR THE FORECAST.
MODELS ARE ALSO IN GOOD AGREEMENT ON BRINGING THE NEXT NORTH PACIFIC
LOW INTO THE WESTERN BERING ON SUNDAY...WITH AN ASSOCIATED FRONT
REACHING THE WESTERN ALEUTIANS TONIGHT AND TRAVERSING THE REST OF THE
CHAIN THROUGH MONDAY.

.SHORT TERM FORECAST...
SOUTHCENTRAL ALASKA...
CALM CONDITIONS CHARACTERIZED BY GENERALLY LIGHT WINDS AND PARTLY
CLOUDY SKIES WILL PREVAIL ACROSS MUCH OF SOUTHCENTRAL AK INTO THE
EARLY PART OF THE WEEK AS HIGH PRESSURE BECOMES ESTABLISHED OVER THE
PRINCE WILLIAM SOUND REGION. THE EXCEPTION WILL BE KODIAK ISLAND
WHERE A RAIN/SNOW MIX AND GUSTY WINDS WILL ACCOMPANY THE ARRIVAL OF
THE FRONT OVER THE WESTERN GULF THIS EVENING AND PERSIST INTO MONDAY
MORNING. TEMPERATURES SHOULD BE WARM ENOUGH TO ALLOW FOR ALL RAIN BY
SUNDAY...WITH A FEW SHOWERS POTENTIALLY MAKING IT AS FAR NORTH AS THE
SOUTHERN KENAI PENINSULA. WILL AGAIN HAVE TO MONITOR THE POTENTIAL
FOR FOG DEVELOPMENT TONIGHT OVER NORTHERN COOK INLET AS HIGH PRESSURE
BECOMES ESTABLISHED AND SUBSIDENCE TAKES HOLD...ALTHOUGH HIGH CLOUDS
MOVING IN TONIGHT MAY LIMIT THIS POSSIBILITY.

SOUTHWEST ALASKA...
SNOW AND GUSTY WINDS WILL OVERSPREAD COASTAL AREAS OF SOUTHWEST
ALASKA AND LEAD TO AREAS OF BLOWING SNOW AS THE FRONT APPROACHES THE
COAST THIS EVENING...PARTICULARLY FOR PORTIONS OF BRISTOL BAY WEST OF
DILLINGHAM. WINDS WILL SUBSIDE AND SNOW WILL TAPER OFF TO SHOWERS ON
SUNDAY AS THE FRONT WEAKENS AND MOVES AWAY FROM THE AREA AND THE
PARENT LOW MOVES INTO THE NORTHEAST PACIFIC.

ALEUTIANS/BERING SEA...
CONDITIONS WILL CONTINUE TO IMPROVE FROM THE CENTRAL AND EASTERN
ALEUTIANS TO THE AKPEN AS THE LOW DEPARTS THE AREA TONIGHT AND
TRANSITORY RIDGING MOVES THROUGH ON SUNDAY. HOWEVER...THE BREAK WILL
BE SHORT LIVED AS ANOTHER FRONT WELL AHEAD OF THE NEXT NORTH PACIFIC
LOW MOVING INTO THE WESTERN BERING REACHES THE WESTERN PART OF THE
CHAIN TONIGHT. A BRIEF WINDOW OF BLIZZARD CONDITIONS WILL BE POSSIBLE
TONIGHT OVER THE WESTERN ALEUTIANS AS STRONG WINDS AND SNOW ARRIVE
WITH THE FRONT. THE BLIZZARD THREAT SHOULD DIMINISH TOWARD MORNING AS
TEMPERATURES CONTINUE TO WARM AND RAIN BEGINS TO MIX IN WITH THE
SNOW. A MIX OF RAIN AND SNOW ALONG WITH GUSTY WINDS WILL THEN
OVERSPREAD THE REST OF THE CHAIN AS WELL AS THE PRIBILOFS AND AKPEN
FROM WEST TO EAST THROUGH MONDAY AS THE WEAKENING FRONT TRAVERSES THE
BERING.

.LONG TERM FORECAST...
HIGH PRESSURE WILL REMAIN IN PLACE OVER THE SOUTHERN MAINLAND THROUGH
THE EARLY PART OF THE WEEK...YIELDING RELATIVELY CALM CONDITIONS FOR
MUCH OF THE AREA. THE RIDGE WILL THEN BEGIN TO BREAK DOWN BY MIDWEEK
AS AN UPPER TROUGH MOVING THROUGH THE BERING ENCROACHES UPON IT FROM
THE WEST...REINTRODUCING A CHANCE OF PRECIPITATION TO THE FORECAST.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WARNING 191
         WINTER WEATHER ADVISORY 161
MARINE...STORM WARNING 175 176
         GALE WARNING 130 132 136 137 138 150 160 172 179 185
         HEAVY FREEZING SPRAY 176
FIRE WEATHER...NONE

CB MAR 13