Small Craft Advisory 389, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
150 PM ADT SAT MAY 3 2008

.ANALYSIS AND UPPER LEVELS...A LONG-WAVE TROUGH IS CENTERED OVER THE
FORECAST AREA WITH UPPER JET TO THE SOUTH OVER THE NORTH PACIFIC AND
GENERALLY WEAK FLOW ACROSS ALASKA. AN ANCHOR LOW REMAINS CENTERED
OVER THE SOUTHEAST BERING WITH A COMPLEX SURFACE LOW SOUTH OF KODIAK
ISLAND TRACKING SLOWLY TOWARD THE GULF. ISOLATED TO SCATTERED SHOWERS
ARE BEING OBSERVED AHEAD OF THIS SYSTEM OVER THE SOUTHERN MAINLAND
AS WEAK UPPER LEVEL WAVES ROTATE THROUGH. SUBSIDENCE ALONG THE MAIN
TROUGH AXIS COMBINED WITH DOWNSLOPE WINDS HAVE HELPED TO SCOUR OUT
MOST OF THE CLOUDS FROM ANCHORAGE TO THE MATANUSKA VALLEY WITH BREAKS
ALSO NOTED ELSEWHERE ACROSS SOUTHCENTRAL. A SURFACE RIDGE IS BUILDING
ALONG THE NORTH GULF COAST ONCE AGAIN TODAY AND LOCALLY GUSTY EAST
TO SOUTHEAST WINDS HAVE DEVELOPED. CONDITIONS IN THE MATANUSKA VALLEY
ARE APPROACHING RED FLAG THRESHOLDS...HOWEVER WITH DIRECTION OF
FLOW DO NOT EXPECT DEW POINTS TO DROP ANY FURTHER. THE BERING REMAINS
UNDER A BLANKET OF STRATUS/STRATO-CU WITH WEAK COLD ADVECTION HELPING
TO SQUEEZE OUT A FEW FLURRIES.

.MODEL DISCUSSION...MODELS REMAIN IN EXCELLENT AGREEMENT AND FEW
CHANGES WILL BE MADE TO CURRENT FORECAST.

.SHORT TERM FORECAST...THE LOW SOUTH OF KODIAK WILL MOVE INTO THE
GULF SUNDAY SPREADING RAIN AND WINDS ACROSS COASTAL AREAS AND OVER
THE ALASKA PENINSULA INTO BRISTOL BAY. THE NORTH GULF COAST RIDGE
WILL BE PUSHED INLAND...SO DO NOT EXPECT A REPEAT OF THE GUSTY
SOUTHEAST WINDS OF THE PAST COUPLE DAYS. THE EASTERN BERING UPPER
LOW WILL OPEN WHILE THE GULF LOW BECOMES DOMINANT. THIS WILL RESULT
IN A NEARLY STATIONARY LOW OVER THE GULF THROUGH MONDAY...WITH MOST
OF MOISTURE REMAINING ALONG THE COAST. INLAND AREAS WILL CONTINUE TO
SEE SUN BREAKS WITH LITTLE OR NO PRECIPITATION.

OUT WEST ANOTHER CLOSED LOW WILL DROP FROM KAMCHATKA DOWN TO THE
ALEUTIANS AND SLOWLY TRACK EASTWARD TO THE EASTERN ALEUTIANS ON
MONDAY. WILL BE INCREASING WINDS ON THE BACK SIDE OF THIS SYSTEM TO
MINIMUM GALES DUE TO DECENT COLD ADVECTION AS UPPER RIDGE BUILDS
UPSTREAM AND NORTHERLY JET STRENGTHENS. NORTHERLY FLOW WILL CONTINUE
ACROSS CENTRAL TO EASTERN BERING THROUGH SUNDAY...MAINTAINING SOLID
CLOUD COVER AND FLURRIES. HOWEVER...AS STORM SYSTEM APPROACHES FROM
WEST SUNDAY NIGHT AND MONDAY SOME OF THIS WILL BEGIN TO BREAK UP AND
CEILINGS WILL RISE.

.LONG TERM FORECAST...MAIN LOW CIRCULATION WILL SET UP OVER THE
BERING SEA NEXT WEEK WITH WEAK RIDGING OVER SOUTHCENTRAL.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE WARNING 120 130 138 172 175 176.
FIRE WEATHER...NONE.

SEB MAY 08