000 AGXX40 KNHC 150800 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 400 AM EDT THU SEP 15 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: 00Z GFS BLEND WITH PREVIOUS OFFICIAL. HIGH CONFIDENCE. A HIGH PRES RIDGE OVER THE SRN UNITED STATES IS MAINTAINING GENTLE TO MODERATE WINDS OVER THE GULF. A WEAK SURFACE TROUGH EXTENDS FROM THE FAR NE GULF SW TO 28N90W...AND SW TO 24N95W. CURRENT BUOY READINGS AND RECENT ALTIMETER DATA SHOW SEAS IN THE RANGE OF 1-3 FT...EXCEPT FOR A PATCH OF 3-4 FT SEAS FROM 26N TO 28N W OF 90W. WAVEWATCH MODEL GUIDANCE HAS BEEN ABOUT 2 FT LESS THAN THESE VALUES THE PAST FEW DAYS. A NARROW UPPER LEVEL TROUGH STRETCHES FROM NRN FL SW TO A SMALL CYCLONIC CIRCULATION AT 26N86W AND TO THE NE YUCATAN PENINSULA. ASSOCIATED BROAD CYCLONIC FLOW COVERS THE BASIN S OF 27N E OF 91W. RESULTANT INSTABILITY COMBINED WITH THAT FROM THE AFOREMENTIONED SURFACE TROUGH EARLIER TRIGGERED OFF SCATTERED SHOWERS AND ISOLATED TSTMS OVER THE ERN HALF OF THE GULF...AND OVER PORTIONS OF THE E CNTRL GULF. THIS ACTIVITY HAS SIGNIFICANTLY DIMINISHED DURING THE OVER NIGHT HOURS...BUT IS EXPECTED TO DEVELOP AGAIN TODAY AND BEGAN TO SHIFT SOME TO THE W WITH THE TROUGH. THE WEAK SURFACE TROUGH IS FORECAST TO SLOWLY MOVE WESTWARD REACHING THE FAR WRN GULF TONIGHT OR EARLY ON FRI. THE 3-4 FT SEAS ARE FORECAST TO SUBSIDE TO 2-3 FT THIS AFTERNOON. ...OTHERWISE LITTLE CHANGE IS EXPECTED IN WIND AND SEA CONDITIONS THROUGH EARLY NEXT WEEK. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: 00Z GFS BLEND WITH PREVIOUS OFFICIAL. HIGH CONFIDENCE. A WEAK PRES PATTERN IS ALSO PRESENT ACROSS THE CARIBBEAN AND TRPCL N ATLC PER LATEST SURFACE ANALYSIS. LATEST ASCAT DATA AND BUOY OBSERVATIONS INDICATE GENERALLY GENTLE TO MODERATE NE-E WINDS THROUGHOUT...EXCEPT FOR MAINLY MODERATE E-SE WINDS IN THE GULF OF HONDURAS AND ALONG THE COAST OF COLOMBIA. SEAS ARE MOSTLY IN THE RANGE OF 3-4 FT IN THE CARIBBEAN...EXCEPT FOR SLIGHTLY HIGHER SEAS OF 4-5 FT S OF 15N BETWEEN 68W-75W AND ALSO IN THE TRPCL N ATLC WATERS. LOWER SEAS OF 2-3 FT ARE OBSERVED W OF 79W...AND IN THE FAR NE CARIBBEAN. WAVEWATCH MODEL GUIDANCE DEPICTS SEAS IN THE TRPCL N ATLC WATERS TO LOWER TO 3-4 FT LATE THIS AFTERNOON INTO THIS EVENING. WATER VAPOR IMAGERY INDICATES AMPLE DEEP LAYER MOISTURE CONTINUING OVER THE MUCH OF THE NW AND N CENTRAL CARIBBEAN. ADDITIONAL MOISTURE IS NOW EVIDENT IN THE SE CARIBBEAN FURTHER ENHANCED BY AN UPPER LEVEL INVERTED TROUGH THERE TRANSLATING WESTWARD ON THE SRN PERIPHERY OF AN UPPER RIDGE THAT STRETCHES SW FROM AN ANTICYCLONE LOCATED JUST NE OF THE LEEWARD ISLANDS TO NW COLOMBIA. THIS MOISTURE HAS TRIGGERED OFF SCATTERED SHOWERS AND TSTMS WITH WITHIN 30 NM OF A LINE FROM 14N64W TO 14N67W TO 14N70W. THIS ACTIVITY IS MOVING QUICKLY WESTWARD. OTHER SCATTERED SHOWER AND TSTM ACTIVITY IS OBSERVED IN THE SW CARIBBEAN DUE TO LOW-LEVEL CONVERGENCE ASSOCIATED WITH A VERY ACTIVE ERN PACIFIC MONSOON TROUGH SEGMENT THERE. THIS ACTIVITY IS EXPECTED TO PERSIST THROUGH THE PERIOD PER LATEST MOISTURE CONVERGENCE GUIDANCE. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: GLOBAL MODEL CONSENSUS. HIGH CONFIDENCE. TROPICAL STORM JULIA WILL MEANDER OFF THE THE S CAROLINA COAST OVER THE NEXT FEW DAYS...OTHERWISE RELATIVELY WEAK HIGH PRES WILL CONTINUE OVER THE BASIN WITH THE ASSOCIATED GRADIENT SUPPORTING GENTLE TO MODERATE E-SE WINDS...EXCEPT FOR THE WATERS BETWEEN THE SE BAHAMAS AND HISPANIOLA WHERE FRESH NE-E WINDS CONTINUE THERE. SEAS WILL BE IN THE RANGE OF 4-6 FT E OF THE BAHAMAS THROUGH EARLY FRI...THEN SUBSIDE TO 3-4 FT AND TO 2-3 FT SAT. HIGHER SEAS IN THE RANGE OF 5-6 FT LINGERING OVER THE FAR NW PORTION DUE TO SWELL GENERATED FROM JULIA WILL SUBSIDE TO AROUND 3-4 FT ON SAT. WAVEWATCH GUIDANCE DEPICTES E SWELL ARRIVING INTO THE FAR SEN WATERS MON WITH COMBINED SEAS BUILDING TO ABOUT 5 OR 6 FT. SEAS SW OF THE BAHAMAS WILL REMAIN AT THE LOW RANGE OF 1-2 FT INTO EARLY NEXT WEEK. .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.