000 AGXX40 KNHC 301846 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 246 PM EDT TUE JUN 30 2015 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W...AND THE SW N ATLANTIC INCLUDING THE BAHAMAS. ...GULF OF MEXICO... MODEL PREFERENCE: FOR WINDS 12Z GFS BLENDED WITH PREVIOUS OFFICIAL FORECAST. USED TAFB NWPS PARAMETERS FOR WAVEHEIGHTS. HIGH CONFIDENCE. A RIDGE EXTENDS FROM SW FL TO THE NE TX COAST WITH A SURFACE HIGH DEVELOPING ALONG THE RIDGE OVER THE E GULF WATERS DURING THE LATE AFTERNOONS AND INTO THE EARLY EVENINGS AS AFTERNOON HEAT TROUGHING DEVELOPS OVER THE FL PENINSULA AND TEMPORARILY SEPARATES THE GULF RIDGE SEGMENT FROM THE ATLC RIDGE. CURRENT BUOY OBSERVATIONS SHOW LIGHT TO GENTLE ANTICYCLONIC WINDS AROUND THE RIDGE AXIS WITH THE EXCEPTION OF HIGHER E-SE WINDS IN THE MODERATE RANGE CONFINED TO THE S AND SW PERIPHERY OF THE RIDGE...AND SW-W 10-15 KT WINDS N OF THE RIDGE OVER THE FAR NE WATERS. NE-E 20-25 KT WINDS WILL MATERIALIZE ALONG THE NW COAST OF THE YUCATAN PENINSULA IN THE EVENINGS AS THE TYPICAL SURFACE TROUGH BEGINS TO MOVE OFF THAT COAST...AND WNW AS AN INVERTED TROUGH DURING THE LATE NIGHT AND EARLY DAYLIGHT HOURS...DISSIPATING BY EARLY IN AFTERNOONS. LATEST SATELLITE IMAGERY SHOWS A VERY ACTIVE AREA OF SCATTERED TO NUMEROUS TSTMS CONTINUING OVER THE FAR WESTERN GULF FROM 22N TO 28N AND BETWEEN 93W-97W DUE TO UPPER DIFFLUENT FLOW NOTED IN THAT PART OF THE GULF AS THE BASE OF A MID/UPPER LEVEL TROUGH SWINGS EASTWARD N OF 26N WHILE BROAD UPPER RIDGING REMAINS S OF 26N W OF 87W. THIS CONVECTION IS EXPECTED TO LINGER INTO WED WHILE DIMINISHING IN COVERAGE. MODELS SUGGEST THAT A SIGNIFICANT THERMAL EVENT WILL BEGIN TO SET UP THIS EVENING WITH E-SE 20-25 KT WINDS S OF 23.5N BETWEEN 90-93W BY LATE TONIGHT. THESE WINDS WILL QUICKLY DIMINISH TO 15-20 KT BY EARLY WED AFTERNOON AS THE TROUGH PULLS OFF TO THE W AS MENTIONED ABOVE AND THE GRADIENT TO ITS E RELAXES. THE RIDGE WILL CONTINUE TO SHIFT N BECOMING ORIENTATED FROM TAMPA BAY TO NE TEXAS BY EARLY THIS EVENING...WHERE IT WILL REMAIN THROUGH THU...THEN SHIFT FURTHER N TO A POSITION FROM CEDAR KEY FL TO THE MS DELTA SAT THROUGH SUN. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: FOR WINDS 12Z GFS BLENDED WITH PREVIOUS OFFICIAL. USED TAFB NWPS PARAMETERS FOR WAVEHEIGHTS. MEDIUM-HIGH CONFIDENCE. ATLC RIDGE N OF THE AREA COMBINED WITH LOW PRES OVER NW COLOMBIA WILL CONTINUE TO MAINTAIN A TIGHT PRESSURE GRADIENT ACROSS THE CARIBBEAN BASIN THROUGH TONIGHT...THEN THE GRADIENT IS FORECAST TO BEGIN TO WEAKEN. NOCTURNAL PULSES TO GALE WARNING FORCE ARE FORECAST TO ONCE AGAIN DEVELOP LATE TONIGHT OVER A SMALL AREA NEAR THE COAST OF NW COAST OF COLOMBIA LATE TONIGHT...WITH SEAS BUILDING TO AROUND 15 FT. MINIMAL GALE WARNING CONDITIONS AREA EXPECTED AGAIN BRIEFLY ON THU NIGHT. THE N EXTENSION OF A TROPICAL WAVE OVER THE CENTRAL PART OF THE GULF OF HONDURAS EARLY THIS AFTERNOON WILL MOVE INLAND BELIZE THIS EVENING. THE NOCTURNAL INCREASE OF TRADES TO 20-25 KT ACROSS THE WESTERN GULF OF HONDURAS IS EXPECTED AGAIN TONIGHT...WITH THESE NOCTURNAL CONDITIONS BEGINNING AGAIN ON FRI NIGHT AND SAT NIGHT. A SECOND TROPICAL WAVE ROUGHLY ALONG 67W WILL RAPIDLY MOVE ACROSS THE EASTERN CARIBBEAN THROUGH TONIGHT...THE CENTRAL CARIBBEAN WED AND WED NIGHT...AND THE WESTERN CARIBBEAN THU THROUGH FRI. A THIRD TROPICAL WAVE APPROACHING THE LESSER ANTILLES EARLY THIS AFTERNOON IS MOVING W AT 20 KT. THIS WAVE WILL ENTER THE FAR EASTERN CARIBBEAN EARLY TONIGHT...MOVE ACROSS THE REST OF THE EASTERN CARIBBEAN LATER TONIGHT INTO WED...THE CENTRAL CARIBBEAN WED NIGHT AND THU...AND POSSIBLY SLOW DOWN OVER THE WESTERN CARIBBEAN THU NIGHT THROUGH SAT BEFORE MOVING INLAND SAT NIGHT. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: FOR WINDS 12Z GFS BLENDED WITH PREVIOUS OFFICIAL. USED TAFB NWPS PARAMETERS FOR WAVEHEIGHTS. HIGH CONFIDENCE. THE MAIN FEATURE IS A RIDGE THAT EXTENDS FROM A 1029 MB HIGH CENTERED WELL NE OF THE BASIN AT 34N50W SW TO S FLORIDA. THE ASCAT PASS FROM 1440 UTC THIS AFTERNOON INDICATED A BROAD SWATH OF SW WINDS OF 20-25 KT N OF 29N BETWEEN 72W AND 76W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE NOTED WITHIN THIS AREA AS WELL. THE FORECAST CONTINUES ON TRACK WITH THE RIDGE SHIFT SLIGHTLY N TO A POSITION FROM 30N65W TO CENTRAL FL ON WED...AND FROM NEAR 29N65W TO E CENTRAL FLORIDA BY THU NIGHT. THE SW 20-25 KT WINDS N OF 29N BETWEEN 72W AND 76W ARE FORECAST TO DIMINISH TO 15-20 KT TONIGHT...THEN START UP AGAIN WITHIN THE SAME GENERAL AREA WED AFTERNOON AND DIMINISH LATE WED NIGHT. SW 15-20 KT WINDS ARE EXPECTED TO BRIEFLY DEVELOP OVER THE NW PORTION ON FRI AS A WEAK TROUGH MOVE OFF THE SE GA COAST. THE TROUGH WILL STALL LATE ON FRI. MODERATE E-SE TRADES ARE OBSERVED S OF THE RIDGE...EXCEPT INCREASING TO 20-25 KT ALONG THE N COAST OF HISPANIOLA AND THE ATLC APPROACH TO THE WINDWARD PASSAGE DURING THE LATE AFTERNOONS INTO EARLY EVENINGS. THESE WIND EPISODES WILL CONTINUE THROUGH THE FORECAST PERIOD. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... .AMZ031...CARIBBEAN FROM 11N TO 15N BETWEEN 72W AND 80W INCLUDING COLOMBIA BASIN... GALE WARNING LATE TONIGHT FROM 11.5N TO 12N BETWEEN 74W AND 75W. GALE CONDITIONS POSSIBLE THU NIGHT. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *FOR DETAILED ZONE DESCRIPTIONS PLEASE VISIT: HTTP://WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF NOTE: GRIDDED MARINE FORECASTS ARE AVAILABLE IN THE NATIONAL DIGITAL FORECAST DATABASE (NDFD) AT: HTTP://WWW.NHC.NOAA.GOV/MARINE/GRIDS.PHP FOR ADDITIONAL INFORMATION PLEASE VISIT: HTTP://WWW.HURRICANE WARNINGS.GOV/MARINE $$ .FORECASTER AGUIRRE. NATIONAL HURRICANE CENTER.