000 AGXX40 KNHC 300717 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 317 AM EDT WED SEP 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: GLOBAL MODEL CONSENSUS. LATEST TAFB NWPS FOR WAVE PARAMETERS. MEDIUM CONFIDENCE. A SHARP UPPER TROUGH ALONG THE COAST OF TEXAS CONTINUES TO PROVIDE SUPPORT TO 1008 MB SURFACE LOW PRES CENTERED IN THE NW GULF NEAR 26.5N93.5W. THIS LOW IS FORECAST TO OPEN UP INTO A TROUGH AS IT TRANSITS THE GULF OVER THE NEXT 48 HOURS. CONDITIONS HAVE IMPROVED MARKEDLY OVER THE EASTERN GULF AS CONVECTIVE ACTIVITY HAS SWEPT N OF THE AREA AND IS FOCUSED MORE ALONG THE EAST COAST OF THE U.S. GLOBAL MODELS INDICATE THE UPPER TROUGH WILL DE-AMPLIFY SLIGHTLY AS IT DRIFTS EAST ACROSS THE GULF THROUGH EARLY THU...THEN BE REPLACED BY A MUCH DEEPER TROUGH LATE THU AND POTENTIAL CLOSED OFF LOW FRI AND SAT. AS A RESULT THE SURFACE TROUGH NOTED ABOVE WILL DRIFT INTO THE SOUTHERN GULF BY THU AND FRI AHEAD OF A COLD FRONT EXPECTED TO SLIP INTO THE NORTHERN GULF BY THU. THIS FRONT WILL SWEEP RAPIDLY SE AND EXTEND FROM TAMPA BAY TO THE BAY OF CAMPECHE MID-DAY FRI AND CLEAR THE GULF BY EARLY SAT WITH FRESH TO STRONG NORTH-NORTHWEST WINDS IN ITS WAKE. DEPENDING ON THE ULTIMATE TRACK OF JOAQUIN WELL N OF THE AREA A SURGE OF STRONG WEST TO NORTHWEST WINDS ARE POSSIBLE OVER THE E GULF LATE SAT INTO SUN WITH THE POTENTIAL FOR HIGHER SEAS TO 8 FT OVER THE FAR E GULF WITH IMPACTS ON THE WEST COAST OF FLORIDA. NO OTHER MAJOR DIFFERENCES IN MODEL OUTPUT ARE NOTED. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: GLOBAL MODEL CONSENSUS. LATEST TAFB NWPS FOR WAVE PARAMETERS. MEDIUM TO HIGH CONFIDENCE. SHIP OBSERVATIONS AND SCATTEROMETER PASSES FROM 0152 AND 0240 UTC INDICATED 15 TO LOCALLY 20 KT TRADE WINDS OVER THE S CENTRAL CARIBBEAN...WITH GENERALLY LIGHT TO GENTLE BREEZES ELSEWHERE. THE SUBTROPICAL RIDGE THAT IS USUALLY NORTH OF THE REGION RESPONSIBLE FOR MUCH OF THE STRONGER TRADE WIND FLOW HAS BEEN DISPLACED BY T.S. JOAQUIN NOW LOCATED 300 NM EAST OF THE NORTHWESTERN BAHAMAS. THIS IS RESULTING IN WELL BELOW NORMAL TRADE WIND FLOW IN THE AREA. THIS TREND WILL CONTINUE AS THE RIDGE AXIS BRIEFLY BECOMES DISPLACED FARTHER SOUTH INTO THE NORTHERN CARIBBEAN. ASIDE FROM LIGHT WINDS...ANOTHER UNUSUAL IMPACT OF THE MOVEMENT OF JOAQUIN NEAR THE BAHAMAS WILL BE ANOMALOUS SW TO W WINDS SPREADING OVER MUCH OF THE NW CARIBBEAN AND THE WINDWARD PASSAGE LATER TODAY INTO THE EARLY PART OF THE WEEKEND. DEPENDING ON THE TRACK AND INTENSITY OF JOAQUIN...THE SW FLOW MAY BE SLIGHTLY STRONGER THAN ANTICIPATED. THE UKMET/GFS MODELS ARE FORECASTING SW WINDS TO 25 NEAR THE WINDWARD PASSAGE LATE THU INTO FRI. OTHERWISE NO MAJOR DIFFERENCES IN MODEL OUTPUT. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: GLOBAL MODEL CONSENSUS AND OFFICIAL NHC FORECAST FOR JOAQUIN WINDS. LATEST TAFB NWPS FOR WAVE PARAMETERS. MEDIUM CONFIDENCE. THE FORECAST FOR THE SW ATLC IS DEPENDENT UPON THE DEVELOPMENT AND MOVEMENT OF T.S. JOAQUIN...NOW CENTERED ABOUT 300 NM EAST OF THE NORTHWESTERN BAHAMAS. JOAQUIN IS FORECAST TO CONTINUE SLOWLY WEST-SOUTHWEST THROUGH THE NEXT 48 HOURS THEN TURN NORTH AND ACCELERATE. LONG PERIOD NE TO E SWELL REMAINS IN PLACE OVER MUCH OF THE REGION N OF 25N AND THE BAHAMAS...THE RESULT OF A LONG FETCH OF EASTERLY WINDS ALONG A FRONTAL BOUNDARY OVER THE CENTRAL ATLC. THERE IS CONSIDERABLE UNCERTAINTY AMONG MAJOR MODELS WITH THE DETAILS OF TRACK...INTENSITY AND TIMING NOT ONLY OF JOAQUIN BUT ALSO THE SURROUNDING ENVIRONMENT. WITH THE CURRENT MOVEMENTS MARINE INTERESTS ALONG THE ATLC EXPOSURES OF THE CENTRAL AND NORTHERN BAHAMAS SHOULD BE AWARE OF HIGHER SEAS ON THE PERIPHERY OF JOAQUIN THROUGH THE NEXT THREE DAYS BEFORE THE STORM MOVES SUFFICIENTLY NORTH OF THE AREA. AS THE STORM AND ITS EFFECTS SHIFT NORTH OF THE AREA BY SUN...EXPECT GENTLE TO MODERATE SW TO W WINDS ACROSS THE REGION...EXCEPT RESIDUAL STRONG SW WINDS N OF 25N AND W OF 73W. SEAS HERE WILL BE SLOW TO SUBSIDE. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... .AMZ117...BAHAMAS INCLUDING CAY SAL BANK... TROPICAL STORM WARNING THU. HURRICANE WARNING THU NIGHT. .AMZ119...ATLANTIC FROM 22N TO 27N E OF BAHAMAS TO 70W... TROPICAL STORM WARNING EARLY TODAY. HURRICANE WARNING TODAY INTO THU NIGHT. $$ *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 COBB. NATIONAL HURRICANE CENTER.