Small Craft Advisory 579, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM AKDT SAT JUL 25 2009

.MODEL DISCUSSION...SYNOPTIC MODEL INITIALIZATIONS REASONABLE WITH
EXCEPTION OF WEAKENING LOW NEAR NUNIVAK ISLAND THIS MORNING.
DEVELOPING LOW CENTER NEAR KODIAK IS HANDLED WELL BY MODELS.
SIGNIFICANT DIFFERENCES OCCUR WITH NEXT CENTER APPROACHING THE AK PEN
TUE. GFS/ECMWF HAVE THE MOST CONSISTENT AND REASONABLE SOLUTIONS WITH
THIS SYSTEM.

.UPPER LEVELS...
THERE APPEARS TO BE VERY LITTLE CHANGE IN THE OVERALL 500 MB PATTERN
THROUGH MID WEEK. THE LONG WAVE EXTENDING THROUGH THE BERING SEA AND
THE NORTH PACIFIC BETWEEN 180 AND 160W HOLDS IN PLACE AS THE RIDGE
SLOWLY BUILDS NORTH ALONG 130-140W.

.SHORT TERM FORECAST...
.EAST...UPPER 980S LOW CENTER SOUTH OF KODIAK ISLAND THIS MORNING IS
MOVING RAPIDLY NORTH AND SHOULD BE IN BRISTOL BAY EARLY SUN MORNING.
HIGH PRESSURE BUILDS ACROSS THE NORTH GULF COAST TONIGHT AND A WEAK
THERMAL TROUGH CONTINUES INLAND. GALES ARE EXPECTED IN THE OFFSHORE
AND SEVERAL COASTAL MARINE AREAS THROUGH TONIGHT. RESULTANT STRONG
GAP FLOWS ACROSS SOUTHCENTRAL AND THE COPPER RIVER BASIN WILL
INCREASE THROUGH THIS AFTERNOON AND EVENING. WINDS IN THE MARINE
AREAS SHOULD DIMINISH ON SUN...HOWEVER GAP FLOWS WILL REMAIN BRISK
INTO EARLY NEXT WEEK.
RAIN ASSOCIATED WITH FRONT MOVING TOWARD THE NORTH GULF THIS EVENING
WILL GENERALLY FALL ALONG THE GULF COAST AND SE EXPOSURES. SE
DOWNSLOPE SHOULD KEEP PRECIPITATION TO A MINIMUM IN VALLEY SECTIONS.

.WEST...A SERIES OF EMBEDDED LOWS IN THE LONG WAVE PATTERN WILL
CONTINUE UNSETTLED WEATHER OVER WESTERN ALASKA THROUGH EARLY NEXT
WEEK. LOW SOUTH OF KODIAK MOVES INTO BRISTOL BAY TONIGHT AND WEAKENS
AS IT TRACKS ACROSS COASTAL SW ALASKA SUN. THIS CENTER WAS SPREADING
RAIN TO BRISTOL BAY THIS MORNING AND WILL CONTINUE TO PUSH MOISTURE
AND COOLER AIR INTO THE REMAINDER OF SW ALASKA TONIGHT. SW ALASKA
WILL SEE A BREAK IN PRECIPITATION MON AS LOW AND ASSOCIATED FRONT
MOVE NORTH...HOWEVER MOISTURE SPREADS BACK INTO THE AK PEN AND
BRISTOL BAY SUN NIGHT AS YET ANOTHER LOW CENTER MOVES TOWARD DUTCH
HARBOR AND ASSOCIATED FRONT HEADS TOWARD SW ALASKA. STRONG GAP FLOWS
ALONG THE ALEUTIAN RANGE...BRISTOL BAY WILL CONTINUE THROUGH TONIGHT
THEN DIMINISH SUN WITH WEAKENING LOW CENTER. WINDS ARE EXPECTED TO
INCREASE AGAIN ACROSS SW ALASKA AND AK PEN SUN NIGHT AS NEXT LOW
MOVES TOWARD DUTCH HARBOR.

.LONG TERM FORECAST...LONG WAVE HOLDING OUT WEST AND SLOWLY BUILDING
RIDGE OVER THE GULF SUGGESTS CONTINUED UNSETTLED WEATHER WEST AND
DRYING AND WARMER IN THE EAST BY MID/LATE WEEK.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...FLOOD WATCH 121 AND 125.
MARINE...GALES 120 130 132 138 140
FIRE WEATHER...RED FLAG WARNING ZONE 141.

RMC JUL 09