000 AGXX40 KNHC 190819 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE MIAMI FL 418 AM EDT SUN JUL 19 2009 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... A PRE-FRONTAL TROUGH PERSISTED OVERNIGHT ACROSS THE EXTREME NRN GULF...AHEAD OF A WEAK COLD FRONT MOVING THROUGH THE DEEP SOUTH STATES AND APPROACHING THE GULF COAST. VERY ACTIVE AFTERNOON CONVECTION OCCURRING BETWEEN THESE BOUNDARIES HAS WEAKENED CONSIDERABLY. HOWEVER...A S/W TROUGH DIVING INTO THE BACKSIDE OF THE UNUSUALLY BROAD AND DEEP UPPER TROUGH ACROSS THE ERN TWO-THIRDS OF THE U.S. WILL ACT TO INITIATE ANOTHER ROUND OF ACTIVE WEATHER AGAIN TODAY...FIRST ACROSS THE NW GULF AND THEN SHIFTING E AND SE ACROSS THE NRN THIRD OF THE BASIN. A WEAK SURFACE HIGH IS SOUTH OF THE PRE FRONTAL TROUGH...W TO E ALONG 25N...AND CENTERED OVER THE SOUTHEAST GULF. WINDS OUTSIDE OF THUNDERSTORMS REMAIN FAIRLY LIGHT ACROSS THE GULF...WITH THE EXCEPTION OF THE EASTERN BAY OF CAMPECHE WHERE AN EVENING QUIKSCAT PASS SHOWED N TO NE WINDS UP TO 20 KT WINDS. THE COLD FRONT WILL PUSH INTO THE N GULF LATER TODAY AND STALL BY AFTERNOON...AND THEN MEANDER AND BECOME DIFFUSE ON MONDAY. THE RIDGE WILL REMAIN IN PLACE...MAINTAINING GENERALLY LIGHT TO MODERATE WINDS INTO EARLY NEXT WEEK. BY MIDWEEK...THE SUBTROPICAL RIDGE WILL BUILD OVER THE WESTERN ATLC AND INTO THE GULF. THIS WILL ALLOW SLIGHTLY STRONGER RETURN FLOW OVER THE WESTERN GULF OF MEXICO. CARIBBEAN... EVENING QUIKSCAT PASSES CONTINUED TO SHOW A BROAD AREA OF 20+ KT WINDS ACROSS MUCH OF THE CARIBBEAN...STILL WITH DEFINITE 25-30 KT WINDS GOING OFF THE COAST OF COLOMBIA IN THE SW CARIBBEAN. ANOTHER LOW TO MID LEVEL WIND PERTURBATION AND ACCOMPANYING WIND SURGE HAS MOVED THROUGH THE CARIBBEAN AND WAS NEARING 78W THIS MORNING...AND ACTING TO MAINTAIN THIS FRESH TO STRONG FLOW ACROSS THE BASIN. THESE FRESH TRADES ARE ALSO BEING AIDED BY A RELATIVELY STRONG ATLC HIGH PRES RIDGE NUDGING INTO THE BAHAMAS AND THE ERN GULF OF MEXICO. AS THE WESTERN PORTION OF THIS HIGH PRES WEAKENS OVER THE NEXT DAY OR SO...WINDS WILL BEGIN TO DIMINISH SOMEWHAT OVER THE SW CARIBBEAN...ALTHOUGH 25 KT ALONG THE IMMEDIATE COAST OF COLOMBIA IS NOT OUT OF THE QUESTION THROUGH THE MIDDLE OF NEXT WEEK. MAXIMUM SEAS IN THE BASIN ARE OCCURRING THERE...AND ARE ESTIMATED TO BE NEAR 13 FT IN E TO NE SWELL. OTHERWISE...THE MAIN WEATHER INFLUENCE WILL BE A TROPICAL WAVE CURRENTLY MOVING ACROSS PUERTO RICO AND THE ERN CARIBBEAN. THE PERTURBATION MENTIONED ABOVE HAS ACTED TO LIFT ITCZ MOISTURE FROM S AMERICA NW INTO THE CENTRAL CARIBBEAN ALONG 14N DURING THE PAST 36 HOURS...AND OUT AHEAD OF THE TROPICAL WAVE. A TUTT LOW TO THE NE OF THE NE CARIB AND ASSOCIATED TUTT AXIS N OF THE GREATER ANTILLES ACTED TO IGNITE WIDESPREAD DEEP CNVTN WITH THE WAVE AS IT ENTERED THE NE CARIBBEAN YESTERDAY. HOWEVER THE WAVE IS NOT ENCOUNTERING AS FAVORABLE AN UPPER ENVIRONMENT ATTM AND WILL PROPAGATE W AND W-NW DURING THE NEXT FEW DAYS WITH CONVECTION MORE SCATTERED. SQUALLS AND ISOLATED TSTMS WILL CONTINUE ALONG THE LEADING EDGE OF THE NRN PORTION OF THE WAVE AS IT CROSSES THE GREATER ANTILLES AND MOVES THROUGH THE BAHAMAS NEXT FEW DAYS. EXPECT A SURGE OF TRADE WINDS BEHIND THE WAVE TO 25 KT...AND SQUALLY WEATHER...WITH SEAS INCREASING WITH THE TROPICAL WAVE PASSAGE. I AM NOT CONFIDENT WITH THE GFS SOLUTION OF THIS WAVE AS IT SEEM TO MOVE IT TOO SLOWLY AND LEAVES SOME TROFFING BEHIND ACROSS THE THE NE CARIBBEAN TODAY...WHILE CURRENT STLT IMAGERY CLEARLY SHOWS A LOW TO MID LEVEL VORT PASSING S OF PUERTO RICO ATTM. I THUS PREFER THE ECMWF AND UKMET SOLUTIONS OF A FASTER MOVING WAVE...WITH MOST OF THE ENERGY AND ACTIVE WEATHER CROSSING THE CARIBBEAN N OF 16N AND ACROSS THE GREATER ANTILLES AND ADJACENT ATLC. A SECOND TROPICAL WAVE CURRENTLY OVER THE CENTRAL ATLC WILL PUSH INTO THE EASTERN CARIBBEAN BY EARLY MONDAY...REACHING ROUGHLY 68W BY EARLY TUE...AND JAMAICA BY WED. ATLANTIC S OF 31N W OF 55W... A STRONG AND PROMINENT SURFACE RIDGE EXTENDS FROM THE AZORES THROUGH THE CENTRAL BAHAMAS AND TO THE FLORIDA STRAITS. A TRIO OF TROPICAL WAVES ARE NOTED OVER THE TROPICAL ATLC WATERS. THE FIRST MENTIONED ALREADY IS MOVING ACROSS THE ERN CARIB. THE SECOND WAS ALONG 49W...AND A THIRD SMALLER WAVE WAS APPROACHING 38W. THE NRN PORTION OF THIS FIRST WAVE WILL TAKE A W-NW MOTION AND MOVE N OF HISPANIOLA TODAY AND INTO THE TURKS AND CAICOS AND SE BAHAMAS THIS AFTERNOON AND EVENING...ACCOMPANIED BY SHOWERS AND SQUALLS...AND INCREASING WINDS AND SEAS. A BROAD WIND SURGE ASSOCIATED WITH THE NRN PORTION OF THIS WAVE WILL BRING A SIGNIFICANT INCREASE IN SEAS TO THE BAHAMAS AND ATLC WATERS TO THEIR E BY MON...BUILDING 7 TO 9 FT OR HIGHER. MEANWHILE SQUALLS AND TSTMS WILL LIKELY PERSIST WITH THIS FEATURE INTO THE CENTRAL BAHAMAS MON AND TUE. OTHERWISE...THE ATLC RIDGE WILL SHIFT SLIGHTLY W AND NW DURING THE NEXT SEVERAL DAYS AND TIGHTEN THE PRES GRADIENT IN CONJUNCTION WITH THE TROPICAL WAVE TO BRING INCREASING E TO SE WINDS OF 20 TO 25 KT OVER THE WATERS TO THE NORTH PUERTO RICO ACROSS THE SOUTHERN BAHAMAS AND TURKS AND CAICOS THROUGH MIDWEEK. WINDS AND SEAS WILL START TO DIMINISH LATER IN THE WEEK AS THE TROPICAL WAVE ACTIVITY RELAXES TO THE SOUTH AND THE SUBTROPICAL RIDGE SHIFTS SOUTHWARD. WARNINGS ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. $$ $$ FORECASTER STRIPLING