Small Craft Advisory 467, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AKDT MON JUN 8 2009

.ANALYSIS AND UPPER LEVELS...
IN THE UPPER LEVELS...RIDGING REMAINS OVER THE EASTERN GULF AND
MAINLAND...WITH A SHORTWAVE RIDGE OVER THE SOUTHERN INTERIOR. A HIGH
AMPLITUDE TROUGH IS STILL IN PLACE OVER THE BERING...WITH A CUT OFF
LOW SOUTH OF THE CENTRAL ALEUTIANS. A ROBUST SHORTWAVE OVER BRISTOL
BAY IS MOVING NORTHWARD INTO SOUTHWESTERN ALASKA.

AT THE SURFACE...HIGH PRESSURE IS BUILDING OVER THE GULF OF
ALASKA...WITH A DEVELOPING THERMAL TROUGH OVER SOUTHCENTRAL. A
WEAKENING LOW EVIDENT ON SATELLITE IMAGERY IS NORTH OF COLD BAY. THIS
LOW WILL DISSIPATE TODAY WHILE MOVING NORTHWARD. ELSEWHERE...A LARGER
LOW CENTERED SOUTHWEST OF ADAK IS SPREADING RAIN ACROSS THE WESTERN
AND CENTRAL ALEUTIANS.

.MODEL DISCUSSION...
MODELS REMAIN IN GOOD AGREEMENT THROUGH WEDNESDAY. AS
USUAL...DIFFERENCES ARISE CONCERNING PLACEMENT AND INTENSITY OF
INDIVIDUAL FEATURES. LITTLE CHANGE WILL BE REQUIRED TO THE ONGOING
FORECAST...WITH A FOCUS ON THE GFS SOLUTION IN THE SHORT TERM FOR THE
MORNING PACKAGE.

.SHORT TERM FORECAST...
.SOUTHCENTRAL...
A SHORTWAVE TROUGH MOVING THROUGH THE AREA TODAY WILL BRING AN
INCREASE IN CLOUDS...BUT LITTLE ELSE IN OTHER SENSIBLE WEATHER
IMPACTS. UPPER RIDGING BUILDING IN TUESDAY AND WEDNESDAY WILL LEAD TO
CONTINUED SUNNY AND WARM CONDITIONS ACROSS MOST OF THE AREA. ONE
EXCEPTION TO THIS WILL BE ALONG THE ALASKA RANGE...WHERE THE THERMAL
TROUGH WILL TRIGGER ISOLATED AFTERNOON SHOWERS. AFTERNOON SEA BREEZES
WILL BE FORMING UNDER WEAK SYNOPTIC FLOW...WITH PATCHY FOG ALONG
COASTAL LOCATIONS UNDER GOOD RADIATIONAL COOLING AT NIGHT.

.SOUTHWEST...
THE DISSIPATING LOW AND ASSOCIATED SHORTWAVE WILL BE AFFECTING
SOUTHWEST TODAY AND TONIGHT...KEEPING THE THREAT OF SHOWERS AROUND
THE AREA. HIGHEST CHANCES OF RAIN OCCUR ALONG COASTAL LOCATIONS.
TUESDAY WILL SEE IMPROVING WEATHER AS UPPER RIDGING BUILDS IN...WITH
WEDNESDAY EXPECTED TO BE WARMER AND GENERALLY FAIR ACROSS THE REGION.

.BERING SEA AND ALEUTIANS...
UNSETTLED WEATHER WILL PERSIST ACROSS THE ISLANDS THROUGH THE MIDDLE
OF THE WEEK AS THE LARGE LOW SOUTH OF ADAK REMAINS NEARLY STATIONARY.
SHORTWAVES ROTATING AROUND THE UPPER LOW WILL ALSO ENHANCE RAIN
POTENTIAL THROUGHOUT THE NEXT SEVERAL DAYS.

.LONG TERM FORECAST...
AS PREVIOUSLY MENTIONED...CONSENSUS IS GOOD IN KEEPING A LARGE
CUT-OFF LOW ALONG THE ALEUTIANS THROUGH THE COMING WEEK. AGREEMENT
ALSO CONTINUES AT WEAKENING THE RIDGE OVER THE EASTERN GULF BY
MIDWEEK. EXPECT COOL AND WET CONDITIONS FOR THE BERING AND
ALEUTIANS...WITH FAIRLY DRY AND WARM CONDITIONS OVER THE SOUTHERN
MAINLAND. THE THERMAL TROUGH WILL REMAIN OVER THE INTERIOR...LEADING
TO AN ENHANCED THREAT OF ISOLATED DIURNAL CONVECTION.

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

NRH JUN 09