000 AGXX40 KNHC 030738 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 337 AM EDT TUE JUL 03 2012 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... A WEAK 1018 MB HIGH REMAINS STATIONARY OVER THE E GULF...AND HAS SHIFTED WITH THE ATTENDANT RIDGE AXIS SLIGHTLY NW TO NEAR 27.5N86W...AND REMAINS WEAKLY CONNECTED TO NWD SHIFTING ATLC RIDGE. LATEST BUOY OBSERVATIONS ARE REPORTING E-SE WINDS OF 10-15 KT OVER JUST ABOUT THE ENTIRE GULF...EXCEPT N OF 27N E OF 87W WHERE SW-W WINDS OF 5-10 KT ARE NOTED. THE BUOYS ARE REPORTING SEAS IN THE RANGE OF 4-5 FT W OF 93W...AND 1-2 FT E OF 93W. THE HIGH AND ASSOCIATED RIDGE WILL BE THE MAIN WEATHER FEATURE KEEPING HOLD ON WIND AND SEA CONDITIONS THROUGH SAT AS A WEAK SURFACE TROUGH MOVES ACROSS THE SE U.S. A TROPICAL WAVE MOVING ACROSS THE CENTRAL CARIBBEAN PRESENTLY IS FORECAST TO REACH THE YUCATAN PENINSULA WED AFTERNOON AND WILL ENHANCE THE TYPICAL AFTERNOON AND EVENING CONVECTION THERE WHICH MAY SPREAD W INTO THE BAY OF CAMPECHE OVERNIGHT WED. FOR THIS FORECAST PACKAGE HAVE CONTINUED TO LEAN HEAVILY TOWARDS THE GFS....WITH THE UKMET VERY SIMILAR...WHILE THE ECMWF RUN FROM 12 UTC YESTERDAY IS A BIT SLOWER WITH THIS WAVE. WWIII GUIDANCE LOOKS REASONABLE FOR THE PERIOD. SOUTHWEST NORTH ATLC S OF 31N W OF 65W... THE MAIN FEATURE FOR THIS PART OF THE ATLC IS THE WELL DEFINED JULY ATLC RIDGE THAT EXTENDS FROM THE CENTRAL ATLC WSW TO THE LAKE OKEECHOBEE REGION OF FLORIDA. A WEAK SURFACE TROUGH IS EXITING W ACROSS THE BAHAMA BANKS AND MOVING INTO THE STRAITS OF FLORIDA EARLY THIS MORNING...AND PRODUCING AN AREA OF LOW TOPPED SCATTERED TSTMS. MODELS ARE IN GENERAL GOOD AGREEMENT THAT THE RIDGE WILL SHIFT SLIGHTLY TO 28N WED THROUGH FRI...AND TO 29N BY SAT. A SLIGHTLY TIGHTER PRES GRADIENT TO THE S OF THE RIDGE WILL MAINTAIN FRESH ELY TRADES ACROSS THE TROPICAL ATLC AND SRN PORTIONS OF THE SW N ATLC INCLUDING THE SE BAHAMAS DURING THE FORECAST PERIOD. SEAS IN THE SRN PORTION OF THE AREA BUILD TO 6-7 FT WED THROUGH FRI WITH POSSIBLE SMALL AND SHORT-LIVED POCKETS OF 8 FT NEAR THE SE BAHAMAS BEFORE SUBSIDING TO 5-6 FT ON SAT. SEAS ELSEWHERE ARE FORECAST TO BE IN THE RANGE OF 2-4 FT NE OF THE BAHAMAS...AND LOWER IN THE 1-3 FT W OF THE BAHAMAS AND ALSO N OF 27N W OF 77W. DO NOT SEE ANY NEED TO DEVIATE FROM THE WWIII GUIDANCE FOR THIS FORECAST PACKAGE. THE FAR NRN FRINGE OF A TROPICAL WAVE CURRENTLY PASSING TO THE S OF THE CARIB ENTRANCE TO THE WINDWARD PASSAGE WILL ENHANCE CONVECTION OVER E CUBA HISPANIOLA LATER TODAY AND INTO CENTRAL PORTIONS TONIGHT. THE NEXT TROPICAL WAVE WILL RACE ACROSS THE ATLC AT 20-25 KT AND REACH PUERTO RICO WED EVENING...THEN MOVE ACROSS THE REMAINDER OF THE CARIBBEAN THROUGH DAY 5 POSSIBLY HELPING TO FIRE UP CONVECTION OVER THE ISLANDS INCLUDING JAMAICA WITHIN ABOUT 36 HRS. THIS IS A LARGE TROPICAL WAVE WITH A BROAD AMPLITUDE...AND SCATTERED CONVECTION IS EXPECTED ALONG THE LEADING EDGE OF CONVERGENCE AND SPREADING N OVER THE SURROUNDING ATLC WATERS OF THE GREATER ANTILLES. LOOK FOR AN INCREASE TO ELY WINDS IN THE FAR SRN ATLC WATERS AS THE WAVE MOVES THROUGH THE REGION. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... FRESH ELY TRADES CONTINUE ACROSS THE CENTRAL CARIBBEAN THIS MORNING...AND WILL BECOME FURTHER ENHANCED THROUGH WED AS THE TROPICAL WAVE ALONG 74/75W CONTINUES TO MOVE W ACROSS THE BASIN AS THE ATLC RIDGE GRADUALLY LIFTS EVER SO SLIGHTLY NWD. LEADING EDGE OF WAVE HAS ENCOUNTERED TUTT LOW S OF JAMAICA OVERNIGHT AND CONVECTION IS LIKELY TO REMAIN ACTIVE ON E SIDE OF LOW. ALTHOUGH TPW ANIMATION SHOWED THAT THE MOISTURE ASSOCIATED WITH THE WAVE HAD DIMINISHED DURING THE DAY YESTERDAY...THE TUTT LOW IS AIDING IN RECREATING LOW TO MID LEVEL CONVERGENCE WITH THIS WAVE...ALSO AIDED BY WEAKER LLVL FLOW ACROSS THE NW CARIB. THE WAVE WILL CONTINUE TO MOVE QUICKLY W AND REACH 81/82W THIS EVENING...AND INTO THE YUCATAN BY WED AFTERNOON. A BROAD FIELD OF 20-25 KT WINDS WILL ENCOMPASS MUCH OF THE CENTRAL CARIB TODAY THROUGH WED AS THIS WAVE MOVES THROUGH...EXTENDING N TO JUST ALONG THE COAST OF HISPANIOLA. SEAS WITHIN THIS WIND AREA ARE STILL FORECAST TO BUILD TO 8-10 FT...WITH AS HIGH AS 12 FT S OF 13N BETWEEN 72W-75W. THE NOCTURNAL WIND MAX OFF OF COLOMBIA SHOULD REACH NEAR 30 KT THE NEXT FEW NIGHTS. AS THE WAVE REACHES CENTRAL AMERICA AND THE YUCATAN WED...THE LONG AND EXTENDED FETCH OF FRESH TRADES WILL BUILD SEAS 10-12 FT BETWEEN 76W AND 82W. HAVE CONTINUED TO TREND TOWARD THE WW ENSEMBLE MEAN AS ALL OTHER MODELS APPEAR TOO LOW FOR THIS LONG OF A FETCH. WITH THE ATLC RIDGE WELL ESTABLISHED...A LONG FETCH OF NE TO E TRADES WILL PERSIST NEXT SEVERAL DAYS ACROSS ALONG AND N OF THE MDR OF THE ATLC...AND MAINTAIN SEAS 6-7 FT ACROSS THE TROPICAL ATLC WATERS. SURGES IN THE TRADES ASSOCIATED WITH ELY IMPULSES AND TROPICAL WAVES WILL RAISE WINDS 20 TO LOCALLY 25 KT AND SEAS 7-8 FT WITH ISOLATED AREAS OF 9 FT. NEXT TROPICAL WAVE CURRENTLY EXITING AFRICA EXPECTED TO REACH ALONG 42W BY THU EVENING. NOTE...GRIDDED MARINE OUTPUT IS AVAILABLE AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE (LOWER CASE) GULF OF MEXICO... .NONE. CARIBBEAN SEA... .NONE. SW N ATLANTIC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ FORECASTER STRIPLING