000 AGXX40 KNHC 010631 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 230 AM EDT WED JUL 01 2009 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... THE MAIN WEATHER FEATURE IN THE GULF CONTINUES TO BE A TROUGH THAT EXTENDS FROM THE NORTHERN YUCATAN TO THE NE GULF. THE TROUGH IS THE DIVIDING LINE BETWEEN WEAK HIGH PRES OVER THE NW GULF AND A SURFACE RIDGE THAT EXTENDS FROM THE BAHAMAS THROUGH WESTERN CUBA INTO THE SE GULF. A STALLED FRONTAL BOUNDARY THAT EXTENDS ACROSS THE FAR NORTHERN GULF IS DISSIPATING AT THIS TIME. IN THE SOUTHERN BAY OF CAMPECHE...A TROPICAL WAVE IS ALONG 95W...MOVING WEST. WINDS REMAIN LIGHT FOR THE MOST PART ACROSS THE GULF...EXCEPT FOR 15 KT SOUTHERLY FLOW IN THE SE GULF BETWEEN THE TROUGH AND THE RIDGE. THE TROUGH DAMPENS OUT AND SHIFTS EASTWARD TODAY AS THE RIDGE STARTS TO BUILD WEST OVER THE GULF. WINDS WILL INCREASE SLIGHTLY OVER THE SOUTH CENTRAL GULF AS THIS HAPPENS INTO THE WEEKEND...ESPECIALLY ALONG THE NW COAST OF THE YUCATAN PENINSULA WHERE LOCAL DIURNAL INFLUENCES WILL BE IN PLAY DURING THE EVENINGS. OVER THE NW GULF...SOUTHERLY RETURN FLOW WILL INCREASE SLIGHTLY AS WELL BY SAT AS THE RIDGE BUILDS WEST. CARIBBEAN... A TROPICAL WAVE WILL MOVE INTO THE FAR EASTERN CARIBBEAN LATER TODAY...SOUTH OF A PROMINENT ATLANTIC SURFACE RIDGE DRAPED TO THE NORTH OF THE AREA ACROSS THE SOUTHERN BAHAMAS AND CENTRAL CUBA. BUOYS AND SCATTEROMETER DATA INDICATE A BROAD SWATH OF 15 TO 20 KT TRADES ACROSS THE CARIBBEAN BASIN CURRENTLY. A 03Z ASCAT PASS SHOWS 25 KT ALONG THE COAST OF COLOMBIA. THE PRESSURE GRADIENT WILL TIGHTEN AS THE WAVE MOVES THROUGH THE REGION SOUTH OF THE STRENGTHENING RIDGE. FORECAST STILL CALLS FOR INCREASING TRADES AND BUILDING SEAS. THE GFS/WAVEWATCH MODELS HAVE BEEN SHOWING THIS FOR A COUPLE OF DAYS ALREADY...AND HAVE BEEN A LITTLE TOO FAST BRINGING UP THE WINDS. BUT GIVEN THE APPROACH OF THE TROPICAL WAVE INTO THE CARIBBEAN COUPLED WITH BETTER EVIDENCE THAT THE RIDGE WILL STRENGTHEN SLIGHTLY...IT'S A GOOD BET THAT WINDS WILL INCREASE A LITTLE MORE. TRADES OFF COLOMBIA WILL LIKELY REACH 30 KT BY TONIGHT OR EARLY THU. EAST SWELL WILL BUILD WITH THE STRONG AND PERSISTENT TRADES...AND SEAS TO 12 FT OVER THE SOUTH CENTRAL TO SOUTHWEST CARIBBEAN ARE POSSIBLE BY TOMORROW. WAVEWATCH IS STILL ADVERTISING 15 FT OFF COLOMBIA BY FRI...A LITTLE HIGHER THAN THE UKMET WAVE MODEL SHOWING 13 FT AROUND THE SAME TIME. HEADING INTO THE WEEKEND...A SURFACE HIGH PRES WILL BUILD BETWEEN PUERTO RICO AND BERMUDA OVER THE CENTRAL ATLC...IN RESPONSE TO TROUGHING TO THE EAST OF THE AREA. THIS IS AHEAD OF ANOTHER TROPICAL WAVE APPROACHING FROM THE EAST...AND WILL SHIFT THE FOCUS OF STRONG WINDS TO THE CENTRAL AND EASTERN CARIBBEAN...ALLOWING E TO SE WINDS OVER THE FAR WESTERN CARIBBEAN TO DIMINISH SLIGHTLY. MEANWHILE...AN UPPER LOW CENTERED S OF JAMAICA AND MOVING WEST WILL ENHANCE CONVECTION OVER THE SOUTH CENTRAL AND SOUTHWEST CARIBBEAN TODAY AND TOMORROW. ATLANTIC S OF 31N W OF 55W... TRADE WIND FLOW OVER THE TROPICAL ATLC WATERS E OF THE WINDWARD ISLANDS WILL INCREASE TODAY IN THE WAKE OF A PASSING TROPICAL WAVE TODAY...AND AS A RIDGE OF HIGH PRES N OF THE AREA BUILDS FROM NOW THROUGH SAT. THE SURFACE RIDGE IS ORIENTED NE TO SW FROM ROUGHLY 26N55W TO CENTRAL CUBA. GENERALLY LIGHT WINDS WILL PERSIST FROM THE NORTHERN LEEWARDS TO AROUND 27N. THE RIDGE STRENGTHENS FRI AND SAT AS AN AREA OF SURFACE HIGH PRES CUTS OFF BETWEEN LEEWARDS AND BERMUDA...IN RESPONSE TO A TROUGH DIGGING INTO THE CENTRAL SUBTROPICAL ATLC WATERS FURTHER EAST. MEANWHILE FURTHER NORTH...A PAIR OF SHORT WAVE TROUGHS WILL MIGRATE EAST AROUND THE BASE OF A DEEP LAYER TROUGH OVER THE U.S. EAST COAST...PUSHING A PAIR OF WEAK SURFACE TROUGHS OFF THE CAROLINA COAST INTO THE WESTERN ATLC THROUGH FRI. THIS MAINTAINS PERSISTENT 15 TO 20 KT FLOW SANDWICHED THE RIDGE AXIS AND THE TROUGHING...OVER THE WATERS BETWEEN N FLORIDA AND BERMUDA...WITH WINDS OCCASIONALLY REACHING 25 KT NEAR THE TROUGHS. SEAS WILL GENERALLY BE LESS THAN 8 FT EXCEPT FOR NEAR THE TROUGHS WHERE THEY MAY REACH UP TO 10 FT. WARNINGS ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FORECASTER CHRISTENSEN. TROPICAL PREDICTION CENTER.