000 AGXX40 KNHC 121824 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 224 PM EDT FRI AUG 12 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: FOR WINDS USED 12Z GFS BLEND WITH PREVIOUS OFFICIAL. FOR SEAS USED A BLEND OF 12Z MWW3 AND TAFB NWPS OUTPUT WITH PREVIOUS OFFICIAL. HIGH CONFIDENCE. A SURFACE LOW AND ASSOCIATED SURFACE TROUGH INLAND OVER ERN LOUISIANA IN COMBINATION WITH UPPER LEVEL DISTURBANCES RIDING ALONG THE OUTER PERIPHERY OF AN ANTICYCLONE CENTERED OVR ERN TEXAS WILL CONTINUE TO SUPPORT SCATTERED TO NUMEROUS SHOWERS AND TSTMS ACROSS THE N CNTRL AND NW GULF THROUGH MUCH OF THE WEEKEND. THIS ACTIVITY REMAINS UNDER A VERY NOTICEABLE DIFFLUENT FLOW PATTERN AS WELL. GUSTY WINDS AND LOCALLY HIGHER SEAS CAN BE EXPECTED WITH THIS ACTIVITY. SURFACE HIGH PRES ACROSS THE CNTRL GULF WATERS WILL SHIFT NORTHWARD TO INLAND THE SRN U.S. BY MON NIGHT. THE CURRENT RIDGE PATTERN SUPPORTS MODERATE TO FRESH S TO SW WINDS OVER THE NRN AND WRN GULF...LIGHT TO GENTLE WINDS IN THE VICINITY OF THE RIDGE AXIS OVER THE CNTRL AND ERN GULF...AND MAINLY MODERATE E TO SE WINDS OVER THE SRN GULF. THE PRES GRADIENT BETWEEN THE RIDGE AXIS AND LOW PRES INLAND OVER TEXAS WILL SUPPORT FRESH SE TO S WINDS OVER THE NW GULF THROUGH SUN. ONCE THE RIDGE AXIS SHIFTS NORTHWARD AND INLAND OVER THE SRN STATES EARLY NEXT WEEK...GENERALLY MODERATE TO LOCALLY FRESH SE WINDS WILL COVER THE GULF BASIN GENERATING SEAS OF 3 TO 5 FT. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: FOR WINDS USED 12Z GFS BLEND WITH PREVIOUS OFFICIAL. FOR SEAS USED A BLEND OF 12Z MWW3 AND TAFB NWPS WITH PREVIOUS OFFICIAL. HIGH CONFIDENCE. LATEST SURFACE ANALYSIS HAS A TROPICAL WAVE ALONG A PSN FROM NW CUBA TO NE HONDURAS AND TO ALONG SE NICARAGUA. EARLIER DEEP CONVECTIVE ACTIVITY NOTED OVER MUCH OF THE NW CARIBBEAN HAS WEAKENED TO SCATTERED SHOWERS AND ISOLATED TSTMS. HOWEVER... LATEST SATELLITE IMAGERY SHOWS A CONCENTRATED AREA OF SCATTERED MODERATE CONVECTION IN CLUSTERS BETWEEN 18N AND 21N BETWEEN JAMAICA AND 82W. THIS ACTIVITY LIES UNDER A DIFFLUENT UPPER FLOW PATTERN BETWEEN AN UPPER LOW SITUATED OVER THE SE BAHAMAS AND BROAD ANTICYCLONIC FLOW THAT EXTENDS FROM THE GULF OF MEXICO TO THE NW CARIBBEAN. THIS ACTIVITY IS LIKELY TO MAINTAIN ITSELF INTO TONIGHT. THE PREVIOUSLY WEAKENED ACTIVITY ASSOCIATED WITH THE WAVE IS EXPECTED TO RE-ACTIVATE THIS AFTERNOON AND EVENING AS IS MOVES WESTWARD ACROSS THE REST OF THE NW CARIBBEAN SEA. A SURFACE TROUGH AXIS EXTENDING FROM NEAR GUADELOUPE TO 14N63W TO 11N64W. THE 1410Z ASCAT PASS INDICATED A WELL PRONOUNCED NE TO SE WIND SHIFT ACROSS THE TROUGH AXIS. THIS TROUGH WILL MOVE WESTWARD TO THE CNTRL CARIBBEAN BY SAT BEFORE DISSIPATING SUN AS SUGGESTED BY BNDRY WIND AND SURFACE MOISTURE MODEL GUIDANCE. THIS TROUGH WILL SUPPORT SCATTERED SHOWERS AND TSTMS OVER THE ERN CARIBBEAN THROUGH SAT AND OVER THE ERN PART OF THE CNTRL CARIBBEAN SAT NIGHT INTO SUN. MODERATE TO LOCALLY FRESH TRADES COVER THE CNTRL CARIBBEAN WHILE GENTLE TO MODERATE TRADES PREVAIL ELSEWHERE. THE TRADES ARE FORECAST TO REACH STRONG INTENSITY...AND INCREASE IN COVERAGE OVER MUCH OF THE CNTRL PORTION OF THE BASIN THROUGH THE WEEKEND AS A TROPICAL WAVE CURRENTLY OVER THE CNTRL ATLC MOVES THROUGH CNTRL CARIBBEAN ON SUN...AND RIDGING OVER THE CENTRAL ATLC BUILDS IN BEHIND IT. FRESH TO STRONG TRADES ARE EXPECTED OVER THE CNTRL CARIBBEAN SUN AFTERNOON THROUGH THE MIDDLE OF NEXT WEEK...WITH MAINLY MODERATE TRADES PREVAILING ELSEWHERE NEXT WEEK. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: FOR WINDS USED 12Z GFS BLEND WITH PREVIOUS OFFICIAL. FOR SEAS USED A BLEND OF 12Z MWW3 AND TAFB NWPS WITH PREVIOUS OFFICIAL. HIGH CONFIDENCE. LATEST SURFACE ANALYSIS HAS A DISSIPATING STATIONARY FRONT DRAPED ACROSS THE FAR NE PORTION OF ZONE 115. HIGH PRES OF 1019 MB IS ANALYZED AT 29N75W WITH A RIDGE EXTENDING WSW ACROSS FL AND TO THE CNTRL GULF OF MEXICO. THE PRES GRADIENT ASSOCIATED WITH THE RIDGE SUPPORTS MODERATE E WINDS S OF 25N...AND GENERALLY LIGHT E-SE WINDS N OF 25N EXCEPT FOR SE-S IN THE FAR NW PART. RECENT ALTIMETER DATA AND CURRENT BUOY OBSERVATIONS REVEAL SEAS IN THE 2-3 FT RANGE...EXCEPT FOR 3-4 FT SEAS E OF THE SE BAHAMAS AND IN THE STRAITS OF FL. THIS FORECAST WILL HAVE VERY LITTLE IN THE WAY OF CHANGES FROM THE PREVIOUS ONE. THE RIDGE WILL CHANGE LITTLE THROUGH SUN NIGHT...THEN BE REPLACED BY SLIGHTLY STRONGER HIGH PRES MON THROUGH WED NIGHT. A WEAK SURFACE TROUGH PRESENTLY WELL E OF THE FORECAST WATERS WILL MOVE ACROSS THE SRN WATERS SAT NIGHT THROUGH TUE. MODERATE E-SE WINDS CAN BE EXPECTED N OF ABOUT 26N...AND MODERATE TO LOCALLY FRESH E-SE WINDS S OF 26N. THE EXCEPTION IS WINDS PULSING TO STRONG INTENSITY ALONG THE NRN COAST OF HISPANIOLA THIS EVENING AND OVERNIGHT TONIGHT...THEN AGAIN ON SAT NIGHT. SEAS WILL BUILD TO 6 FT IN THE STRAITS OF FL ON SAT AND CONTINUE THROUGH MON NIGHT BEFORE SUBSIDING TO 5 FT TUE. SEAS ELSEWHERE ARE FORECAST TO VARY LITTLE DURING THIS FORECAST PERIOD. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS II COLLABORATION CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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.