Small Craft Advisory 247, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKDT MON MAR 18 2013

.MODEL DISCUSSION...
FORECAST GUIDANCE IN GOOD AGREEMENT AGAIN TODAY. SOME DIFFERENCES
CROP UP STARTING AROUND 60 HOURS WITH A FRONT IN THE WESTERN BERING
SEA BUT THIS IS FAR ENOUGH OUT THAT A COMPROMISE SOLUTION CAN BE
USED.

.ANALYSIS AND UPPER LEVELS...
THE BASIC PATTERN CONSISTS OF AND UPPER LEVEL HIGH OVER THE BERING
SEA AND AN UPPER LEVEL LOW OVER NORTHWEST CANADA AND NUDGING INTO
EASTERN ALASKA. THERE IS ALSO AN UPPER LOW OVER THE NORTHERN GULF OF
ALASKA THAT IS MOVING EAST. A WEATHER FRONT OVER THE ALEUTIANS IS
ASSOCIATED WITH A LOW WELL TO THE SOUTH THAT IS MOVING EVEN FURTHER
SOUTH. THE UPPER LEVEL FLOW IS NOW NORTHERLY OVER ALMOST ALL OF
MAINLAND ALASKA AND THE ALASKA PENINSULA (AKPEN).

.SHORT TERM FORECAST...
THE CANADIAN UPPER LEVEL LOW WILL SLOWLY DRIFT WEST THROUGH THURSDAY
AND BE CENTERED NEAR KOTZEBUE THURSDAY AFTERNOON. THE BERING SEA
RIDGE WILL BUILD THROUGH TUESDAY MORNING THEN WEAKEN TUESDAY
AFTERNOON THROUGH THURSDAY. THE FLOW ALOFT WILL GO FROM NORTHERLY ON
TUESDAY TO NORTHWESTERLY WEDNESDAY TO WESTERLY ON THURSDAY.

FOR SOUTH CENTRAL ALASKA...DRY CONDITIONS WILL CONTINUE THROUGH
THURSDAY WITH THE FLOW ALOFT FROM MAINLY CONTINENTAL SOURCES. GAP
WINDS WILL INCREASE TONIGHT AND REMAIN FAIRLY GUSTY THROUGH
WEDNESDAY NIGHT BEFORE EASING OFF ON THURSDAY WHEN THE UPPER FLOW
TURNS WESTERLY.

FOR SOUTHWEST ALASKA...CONDITIONS WILL DRY OUT TONIGHT...AND DRY
COLD NORTHERLY FLOW WILL CONTINUE THROUGH TUESDAY NIGHT. ON
WEDNESDAY A WEAK SYSTEM IN THE NORTHWEST FLOW WILL BRING ONLY A
SLIGHT CHANCE OF PRECIPITATION TO THE AREA...MAINLY FOR THE
KUSKOKWIM VALLEY AND DELTA. AS THE FLOW TRANSITIONS TO WESTERLY ON
THURSDAY A SHORT WAVE RIDGE SHOULD KEEP THE AREA DRY.

FOR THE BERING SEA/ALEUTIAN ISLANDS...
MOST OF THE PRECIPITATION AND WINDS WILL REMAIN OVER THE SOUTHERN
BERING SEA AND THE CENTRAL AND WESTERN ALEUTIANS THROUGH TUESDAY
NIGHT AS THE FRONT REMAINS STUBBORNLY IN PLACE. ON WEDNESDAY A LOW
WILL MOVE INTO THE WESTERN BERING SEA AND BEGIN TO PUSH EASTWARD.
ALTHOUGH THE MODELS DISAGREE ON SOME DETAILS...THIS EASTWARD PUSH
WILL PROBABLY REACH THE PRIBILOFS AND EASTERN BERING SEA ON
THURSDAY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE WARNING 150 172 175 176.
         HEAVY FREEZING SPRAY 130 160 165.
FIRE WEATHER...NONE.

LUDWIG MAR 13