000 AGXX40 KNHC 201858 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 300 PM EDT THU AUG 20 2009 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... SE TO S FLOW PREVAILS ACROSS THE GULF BASIN AT AROUND 10 KT WITH SOME POCKETS OF NEAR 15 KT. THIS IS PRODUCING SLIGHTLY HIGHER SEAS THAN FORECAST BY WWIII...WITH BUOY OBS REPORTING 3 FT SEAS ACROSS THE MAJORITY OF THE BASIN. A WEAK HIGH WILL SETTLE ACROSS THE CENTRAL GULF AND DRIFT SW OVER THE NEXT FEW DAYS TO PRODUCE LIGHT AND VARIABLE WINDS AND SLIGHT SEAS. A WEAK FRONTAL TROUGH IS FORECAST TO SINK INTO THE N GULF OVER THE WEEKEND AND ACT AS THE FOCUS FOR TSTM ACTIVITY ACROSS THE FAR N GULF. CARIBBEAN... BILL HAS DISRUPTED THE TYPICAL TRADE WIND FLOW ACROSS THE CARIBBEAN...WITH WEAK LOW LEVEL TROUGHING EXTENDING FROM BILL SW INTO THE NE CARIB...WITH SLY FLOW ON THE E SIDE OF THIS TROUGH...AND MODERATE NE TO E FLOW TO THE W...AND COVERING THE WRN TWO-THIRDS OF THE BASIN. WINDS WERE GENERALLY 15 KT OR LESS THIS MORNING...WITH SMALL ZONES OF 15-20 KT DOWNSTREAM OF THE WINDWARD PASSAGE AND IN THE LEE OF CUBA. MODERATE TRADES WILL BEGIN TO RETURN OVER THE WEEKEND WITH 8-9 FT SEAS RETURNING TO THE SRN CARIB S OF 14N. ATLANTIC W OF 55W... MAJOR HURRICANE BILL REMAINS THE BIG STORY TODAY...WITH A SOMEWHAT LARGE WIND FIELD...AND VERY LARGE WAVE FIELD. A FE ALTIMETER PASSES IN THE PAST 24 HOURS SUGGEST THE GFDL BASED N ATLC HURRICANE VERSION OF WWIII IS DOING VERY WELL...BUT HAVE STILL HAD TO EXPAND THE WAVE FIELD ON THE WRN SEMICIRCLE OF THIS SYSTEM BASED ON SEVERAL BUOY REPORTS N OF THE NE CARIB. BUOY 42059 IN THE E CENTRAL CARIB CLIMBED TO 8 FT THIS MORNING INDICATING NE SWELL FROM BILL LEAKING THROUGH THE ANEGADA PASSAGE...AND ALSO VERIFYING A LARGE WAVE FIELD STILL IN THE SW QUADRANT. THE GENERAL STRAIGHT LINE MOTION OF BILL THE PAST 48 HOURS HAS GENERATED A LARGE WAVE FIELD OF SELY SWELL THAT ARE AIMED AT THE MID ATLC COAST OF THE U.S. AND WILL EXCEED 12 FT FROM THE COASTAL WATERS OF NRN FLORIDA BEYOND THE OUTER BANKS...AT 15-16 SECONDS. THIS WILL PRODUCE HUGE SURF FOR THE EAST COAST AND INDUCE WIDESPREAD COASTAL EROSION AND EXTREMELY DANGEROUS RIP CURRENTS. LONG PERIOD SWELL IS FORECAST TO MOVE INTO THE E COAST OF FLORIDA BY 18Z FRI AND BUILD RATHER QUICKLY OVERNIGHT...AND PEAK AT 8 TO 11 FT IN THE NEAR SHORE WATERS...BRINGING HIGH SURF FROM PALM BEACH NORTHWARD. HIGH SURF IS CURRENTLY AFFECTING THE VIRGIN ISLANDS...PUERTO RICO...AND HISPANIOLA...BUT WILL DROP QUICKLY ACROSS THE VIRGIN ISLANDS AND PUERTO RICO THIS EVENING/TONIGHT...AND SLIGHTLY SLOWER ACROSS HISPANIOLA LATE TONIGHT...AS THE NW MOTION OF BILL IS NOT CONDUCIVE FOR EXTENDED WAVE GROWTH...BUT THE LARGE WIND FIELD HAS COMPENSATED FOR THIS. WARNINGS ATLC... HURRICANE WARNING N OF 19.5N...AMZ087. HURRICANE WARNING N OF 23N E OF 70W FRI AND FRI NIGHT...AMZ080. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE $$ FORECASTER STRIPLING