Small Craft Advisory 486, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
400 PM ADT WED JUN 11 2008

.MODEL DISCUSSION...MODELS SEEM TO BE PERFORMING VERY WELL TODAY.
EVEN OUT TO 120 HOURS THE GFS AND ECMWF HAVE THE EXACT SAME PATTERN
WITH JUST A LITTLE DIFFERENCE IN POSITIONING OF THE DOMINANT LOW AND
HIGH AT THAT TIME. ONLY OTHER DIFFERENCE WORTH MENTIONING IS ON
SATURDAY AFTERNOON WHEN THE GFS HAT THE LOW IN THE WESTERN ALEUTIANS
A BIT STRONGER AND FARTHER WEST THAN THE ECMWF. UPPER LEVEL PATTERN
SEEMS TO FAVOR THE GFS POSITIONING SO THAT WILL BE THE PREFERRED
SOLUTION AT THAT TIME IN THE WESTERN BERING SEA.

.ANALYSIS AND UPPER LEVELS...DRIVING FORCE IN THIS WEATHER PATTERN IS
THE UPPER LEVEL LOW CENTERED NEAR NORTON SOUND. THE UPPER LEVEL
TROUGH WITH THIS LOW EXTENDS OVER KODIAK ISLAND WHERE IT IS
DEVELOPING A CUT OF LOW. THIS CUT OFF LOW WILL HEAD EASTWARD ACROSS
THE GULF OF ALASKA WHERE IT WILL SLIGHTLY STRENGTHEN A WEAK LOW IN
THE GULF BUT THIS SYSTEM SILL HAVE VERY LITTLE EFFECT OF THE WEATHER
IN THE FORECAST AREA. THE MAIN UPPER LEVEL LOW WILL FOLLOW THE TROUGH
TO KODIAK ISLAND ON FRIDAY AND THEN GO EASTWARD ACROSS THE GULF IN
BASICALLY THE SAME TRACK AS THE CUT OF LOW.

SURFACE HIGH PRESSURE IS OVER THE CENTRAL BERING SEA. THIS HIGH WILL
MOVE SLOWLY EASTWARD AND TO THE SOUTHWEST ALASKA COAST BY SUNDAY.

.SHORT TERM FORECAST...SCATTERED SHOWERS SHOULD PERSIST FOR MOST OF
SOUTHERN ALASKA THROUGH THE EVENING AND THEN BE DIMINISHING. EXCEPT
FOR POSSIBLY IN THE EXTREME NORTH AND NORTHEAST PARTS OF THE COPPER
RIVER BASIN THERE SHOULD BE NO THUNDERSTORM ACTIVITY THIS AFTERNOON
OR EVENING.

.LONG TERM FORECAST...WEEKEND STILL LOOKING REASONABLY GOOD FOR THE
MAINLAND PORTIONS OF THE FORECAST AREA. RIDGE IS BUILDING INTO
SOUTHWESTERN ALASKA BY THAT TIME. SHOULD BE ENOUGH SUBSIDENCE TO
SUPPRESS CONVECTION IN SOUTHWEST ALASKA EXCEPT FOR NEAR THE ALASKA
AND ALEUTIAN RANGES. THE SUSITNA VALLEY WILL LIKELY SEE AFTERNOON AND
EVENING CONVECTION AS WELL AS SOME IN THE COPPER RIVER BASIN THIS
WEEKEND.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.

JUN 08