000 AGXX40 KNHC 250750 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 350 AM EDT SAT APR 25 2009 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. LITTLE CHANGE IN OVERALL PATTERN EXPECTED DURING THE NEXT 24 HOURS..AND THEN ONLY MINOR SHIFTING OF ATLC RIDGE THROUGH MID WEEK. GULF OF MEXICO... STRONG RIDGE EXTENDING FROM 1031 MB HIGH OVER W ATLC...WSW INTO NE GULF WILL MAINTAIN A STEADY E TO SE FLOW ACROSS ENTIRE GULF THROUGH THE FORECAST PERIOD. WWIII FORECASTING SEAS TO BUILD 8-9 FT ACROSS NW GULF BY SAT NIGHT. STRONG ELY WINDS ACROSS PORTIONS OF THE SE GULF AND THROUGH THE FLORIDA STRAITS SUGGESTED TO NEAR 30 KT BY EVENING SCATTEROMETER PASSES AND COASTAL OBS...AND BLOWING DIRECTLY AGAINST THE FLORIDA CURRENT...INDUCING HIGHER STEEPER WAVES 10 TO 12 FT...AND POSSIBLY AS HIGH AS 15-16 FT. WAVE MODELS DO NOT HANDLE THIS TYPE OF SITUATION WELL. SW N ATLC... DEEP LAYERED NW ATLC TROUGH THAT SUPPORTED A SURFACE FRONTAL BOUNDARY HAS BEGUN TO FILL AND BECOME MORE ELONGATED...MOVING SLOWLY E ACROSS THE NW ATLC. THIS FRONT HAS EFFECTIVELY STALLED ACROSS THE W CENTRAL ATLC...WITH STRETCHING OF BOUNDARY OCCURRING ACROSS THE SW ATLC AS E TO NELY TRADES WERE PUSHING THE TAIL END OF THIS OLD BOUNDARY WWD AS A WEAK WARM FRONT... THROUGH THE CENTRAL BAHAMAS AND APPROACHING THE NW BAHAMAS. N OF THIS BOUNDARY STRONG SUBSIDENCE IS MAINTAINING DRY FAIR WEATHER...BUT ALSO PRODUCING A 5 DEG SWATH OF 20-25 KT WINDS FROM THE W CENTRAL ATLC...ACROSS THE BAHAMAS AND THEN ACROSS S FL AND THROUGH THE STRAITS. WARM WATERS ACROSS THE REGION ARE AIDING IN PRODUCING A STEEP LOW LEVEL LAPSE RATE AND ALLOWING A GOOD PORTION OF THESE STRONG LOW LEVEL WINDS TO MIX DOWN TO THE SURFACE. LITTLE CHANGE IN THIS FLOW IS EXPECTED THROUGH MONDAY. THIS FRESH TO STRONG NE TO E FLOW ACROSS THE ENTIRE BASIN... WITH LOCALIZED AREAS REACHING 30 KT...WILL MAINTAIN A LONG FETCH ON THE SE SIDE OF THE RIDGE...AND YIELD INCREASING SWELLS S OF 25N...ALSO PROPAGATING THROUGH THE PASSAGES INTO THE GULF AND CARIBBEAN. 7 TO 9 FT SEAS ACROSS THIS REGION OVERNIGHT ARE EXPECTED TO BUILD 9 TO 12 FT BY SUNDAY IN MODERATE PERIOD SWELL. MODELS HINT AT THIS SOLID HIGH PRES RIDGE WEAKENING LATE TUE AND WED...BUT A REINFORCING UPPER LEVEL LONGWAVE RIDGE MIGHT MAKE THIS MINOR. CARIBBEAN AND TROPICAL N ATLC... THE HEALTHY PRES GRADIENT BETWEEN THE W ATLC HIGH AND THE SEMIPERMANENT COLOMBIAN LOW WILL PREVAIL FOR THE NEXT SEVERAL DAYS. THIS WILL CONTINUE TO DRIVE THE TRADES TO NEAR 30 KT ALONG COAST OF COLOMBIA...AND MAINTAIN AN EXPANDED COVERAGE OF 20-25 KT ACROSS ALL BUT THE FAR EASTERN CARIBBEAN. SEAS WILL BUILD 7 TO 9 ACROSS THE E CARIB...AND 9 TO 11 FT WRN CARIB...EXCEPT AROUND 12 FT OFF THE COLOMBIAN COAST. THE TROPICAL ATLC WILL ALSO REMAIN UNDER FRESH TO STRONG TRADES E OF THE ISLANDS WITH THE SE PERIPHERY OF THE W ATLC HIGH PRES RIDGE PRODUCING A LONG FETCH AIMED AT THE ISLANDS...AND BUILDING NE SWELLS 8 TO 10 FT BY SUN. ATLC... .NONE.. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FORECASTER STRIPLING. TROPICAL PREDICTION CENTER.