000 AGXX40 KNHC 171845 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 245 PM EDT TUE MAY 17 2016 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: 12 UTC GFS BLENDED WITH PREVIOUS OFFICIAL FORECAST FOR WINDS. FOR WAVEHEIGHTS BLENDED 12Z MWW3/TAFB NWPS OUTPUT WITH PREVIOUS OFFICIAL. HIGH CONFIDENCE. A STRONG UPPER LEVEL SHORTWAVE TROUGH IS NOW OVER THE ERN GULF WITH NUMEROUS LARGE TSTM COMPLEXES NOTED N OF 25N E OF 89W. LIGHTNING DENSITY DATA INDICATED FREQUENT LIGHTNING WITH THIS ACTIVITY. AS THE TROUGH CONTINUES TO ADVANCE EASTWARD...THIS ACTIVITY WILL SPREAD FARTHER E AND NE OVER THE NE GULF THROUGH TONIGHT...AND INTO WED. THE HEAVIEST OF THE ACTIVITY IS FORECAST TO SHIFT E OF THE GULF DURING WED AFTERNOON. STRONG GUSTY WINDS CAN BE EXPECTED WITH THIS ACTIVITY. CURRENT BUOYS ARE REPORTING MODERATE SE WINDS...EXCEPT LIGHT TO MODERATE S-SW WINDS W OF 86W. THE BUOYS ARE REPORTING SEAS IN THE 1-3 FT RANGE E OF 691W...AND 3-4 FT W OF 91W. A WEAK RIDGE EXTENDS FROM HIGH PRES OVER THE EASTERN U.S. SEABOARD SW TO THE NE GULF WATERS. THE RIDGE WILL SHIFT E OF THE AREA TONIGHT AS A WEAK COLD FRONT APPROACHES THE NRN GULF COAST.THE FRONT WILL STALL WED...AND SLOWLY DISSIPATE THROUGH THU.HIGH PRES FROM THE ATLC WILL BUILD SSW OVER THE NE AND N CENTRAL WATERS THU NIGHT AND FRI...THEN BEGIN TO SLIDE EASTWARD FRI NIGHT THROUGH SAT NIGHT AS ANOTHER WEAK COLD FRONT PASSES JUST TO THE N OF THE GULF. A THERMAL TROUGH WILL DEVELOP OVER THE YUCATAN PENINSULA EACH DAY AND MOVE WESTWARD ACROSS THE SW GULF DURING THE EVENINGS AND DISSIPATE EACH MORNING. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: FOR WINDS USED A BLEND OF THE 12 UTC GFS/00 UTC ECMWF WITH PREVIOUS OFFICIAL FORECAST FOR WINDS. FOR WAVEHEIGHTS BLENDED 12Z MWW3 WITH 00Z ECMWF AND A SMALL PERCENTAGE OF TAFB NWPS OUTPUT WITH PREVIOUS OFFICIAL. HIGH CONFIDENCE. BOTH BUOYS AND A FEW SHIP OBSERVATIONS REVEAL MODERATE TO FRESH E WINDS ACROSS THE CENTRAL CARIBBEAN AND MODERATE E WINDS ELSEWHERE. THE OBSERVATIONS ALONG WITH EARLIER ALTIMETER DATA REVEAL SEAS IN THE RANGE OF 7-10 FT S OF 17N BETWEEN 70-78W WITH HIGHER SEAS OF 10-13 FT FROM 11N-14N BETWEEN 74W-76W. SEAS ELSEWHERE ARE IN THE 3-5 FT RANGE...EXCEPT FOR LOWER SEAS OF 2-3 FT N OF 13N W OF 82W. LATEST MODEL RUNS IN AGREEMENT THAT THE CURRENT PRES GRADIENT WILL SUPPORT FRESH TO STRONG E TRADES IN THE S CENTRAL CARIBBEAN...AND ALONG THE COAST OF COLOMBIA THROUGH FRI AFTERNOON...THEN DIMINISH TO MODERATE TO FRESH CATEGORY THROUGH SAT NIGHT...AND MAINLY MODERATE CATEGORY SUN. SEAS OF 7-10 FT IN NE-E SWELL WILL PROPAGATE W AWAY FROM THE FRESH TO STRONG NE-E TRADES...AND TO POSSIBLY AS W AS 82W TONIGHT. THESE SEAS WILL GRADUALLY SUBSIDE THROUGH FRI AS THE SWELL ENERGY DISSIPATES. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: FOR WINDS USED A BLEND OF THE 12 UTC GFS/00UTC ECMWF WITH PREVIOUS OFFICIAL FORECAST FOR WINDS. FOR WAVEHEIGHTS BLENDED 12Z MWW3 WITH 00Z ECMWF AND A SMALL PERCENTAGE OF TAFB NWPS OUTPUT WITH PREVIOUS OFFICIAL. HIGH CONFIDENCE...EXCEPT AVERAGE CONFIDENCE FRI THROUGH SAT NIGHT. THE PRELIMINARY 18Z ANALYSIS HAS A WEAK TROUGH EXTENDING FROM 30N65W SW TO 28N74W. A SURFACE TROUGH IS ANALYZED FROM 28N71W TO THE SE BAHAMAS. PARTIAL ASCAT DATA FROM 1408Z AND BUOY OBSERVATIONS THROUGHOUT SHOW GENTLE TO MODERATE E-SE WINDS ...EXCEPT FOR GENTLE TO MODERATE SE-S WINDS IN THE FAR NW PART OF THE AREA. SEAS ARE IN THE RANGE OF 3-5 FT E OF THE BAHAMAS...AND 1-3 FT W OF THE BAHAMAS. THE SURFACE TROUGH WILL LIFT NW THROUGH TONIGHT AS DEPICTED IN MOISTURE GUIDANCE FIELDS FROM THE GFS. HIGH PRES RIDGE JUST N OF THE AREA WILL SHIFT EASTWARD THROUGH FRI. A WEAK COLD FRONT WILL MOVE ACROSS THE NW WATERS WED AND WED NIGHT...AND ACROSS THE N CENTRAL AND NE WATERS THU THROUGH FRI BEFORE STALLING OUT OVER THE FAR NE WATERS LATE FRI. THE FRONT WILL DISSIPATE SAT AS YET ANOTHER WEAK COLD FRONT APPROACHES THE FAR NW PORTION. HIGH PRES WILL EXTEND ALONG 27N E OF THE BAHAMAS SAT AND SAT NIGHT. MODEL CONSENSUS IS IN VERY GOOD AGREEMENT THAT WINDS AND SEAS WILL BE IN THE LOW RANGE FOR DAYS 3-5. A MINOR EXCEPTION IS E SWELL EXPECTED TO PRODUCE SEAS OF 5-7 FT IN ZONE 127 WED THROUGH THU BEFORE SUBSIDING TO 4-6 FT THU NIGHT. S OF 22N...THE PRES GRADIENT N OF HISPANIOLA WILL BECOME STRONG ENOUGH TO AGAIN SUPPORT FRESH TO STRONG TRADES WED AFTERNOON...DIMINISHING TO 15-20 KT WED NIGHT. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS II COLLABORATION CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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.