Small Craft Advisory 224, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKDT MON MAR 11 2013

.MODEL DISCUSSION...SYNOPTIC SCALE SOLUTIONS ARE IN FAIR AGREEMENT
THROUGHOUT THE SHORT TERM. THE NAM MODEL WILL BE USED PRIMARILY IN
THE EAST FOR HIGHER RESOLUTION DETAILS.

.ANALYSIS AND UPPER LEVELS...
.UPPER LEVELS...STACKED LOW OVER THE GULF WILL DRIFT SLOWLY SOUTH AND
EAST OVER THE NEXT COUPLE OF DAYS AS A HIGH AMPLITUDE RIDGE BUILDS
OVER THE EASTERN BERING SEA.

.SURFACE...WEAK LOW PRESSURE OVER THE NE GULF IS SLOWLY WEAKENING AND
DRIFTING SOUTH. SKIES ARE CLEARING ACROSS MUCH OF THE MAINLAND AS
HIGH PRESSURE BUILDS IN FROM THE NORTH AND WEST. AREAS OF PATCHY FOG
ACROSS PORTIONS OF THE MATANUSKA VALLEY AND ANCHORAGE BOWL WILL BE
THE LAST IN THESE AREAS FOR THE NEXT SEVERAL DAYS AS NORTHERLY WINDS
SET UP. HIGH PRESSURE WAS EVIDENT OVER THE EASTERN BERING SEA WITH A
STALLED WEATHER FRONT ACROSS THE WESTERN BERING SEA.

THE SHORT TERM FORECAST...
.SOUTHCENTRAL ALASKA...N/S PRESSURE GRADIENTS WILL INCREASE ACROSS
MUCH OF SOUTHCENTRAL AS HIGH PRESSURE BUILDS OVER THE MAINLAND AND
WEAK LOW PRESSURE TROUGHING CONTINUES OVER THE GULF OF ALASKA. THE
RESULT WILL BE BRISK OUTFLOW WINDS ACROSS THE REGION...ESPECIALLY
ACROSS THE NORTH GULF COAST. WARNING LEVEL WINDS ARE EXPECTED THROUGH
THOMPSON PASS AND THE COPPER RIVER DELTA BEGINNING TONIGHT AND
CONTINUING THROUGH TUE. TO A LESSER EXTENT STRONG WINDS ARE EXPECTED
THROUGHOUT THE MATANUSKA VALLEY AND PORTIONS OF THE EASTERN KENAI
PEN. ONE DETRACTOR IS THE LACK OF STRONG COLD ADVECTION AND 500 MB
WIND SUPPORT...HOWEVER...PRESSURE GRADIENTS AND 850 MB SUPPORT SHOULD
BE ENOUGH TO PRODUCE BRISK WINDS ACROSS THE REGION AND LOW END
WARNING LEVEL WINDS IN ZONES 131 AND 135.

.SW ALASKA...
HIGH PRESSURE OVER THE EASTERN BERING SEA WILL GENERATE LOCALLY BRISK
NORTHERLY WINDS AND DRY CONDITIONS OVER MUCH OF SW ALASKA OVER THE
NEXT DAY OR SO.

.BERING SEA ALEUTIANS...

A WEAKENING FRONTAL ZONE AND SERIES OF WEAK NORTH MOVING WAVES WILL
INFLUENCE THE WEATHER OVER THE WESTERN ALEUTIANS/WESTERN BERING SEA
OVER THE NEXT COUPLE OF DAYS. THE RIDGE TO THE EAST WILL SLOW ANY
EASTWARD MOVEMENT OF THE FRONTAL ZONE. EXPECT CLOUDY CONDITIONS WITH
RAIN OR MIX OVER WESTERN AREAS. SOUTHERLY FLOW OVER THE COLD BERING
SEA WATERS WILL ALSO PRODUCE WIDESPREAD FOG.

.LONG TERM FORECAST...
THE AMPLIFIED PATTERN THAT IS SETUP OVER THE REGION CURRENTLY WILL
BREAK DOWN TOWARD THE END OF THE WEEK BRINGING MUCH MORE ZONAL FLOW.
THIS WILL ALLOW A SERIES OF LOWS TO PROGRESS ACROSS THE AREA BRINGING
BACK SHORT LIVED PERIODS OF PRECIP TO MUCH OF THE SOUTHERN PART OF
THE STATE. THIS WILL ALSO PUSH SOME OF THE COLDER TEMPERATURES BACK
TO THE NORTH.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...HIGH WIND WARNING 131 AND 135
MARINE...STORM...127
         GALES...121 128 130 132 128 175 176 191 411 352
         HEAVY FREEZING SPRAY...126 127 128 140
FIRE WEATHER...NONE.

RMC MAR 13