000 AGXX40 KNHC 310717 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 317 AM EDT FRI JUL 31 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: LATEST GFS BLENDED WITH PREVIOUS/OFFICIAL FORECAST FOR WINDS. LATEST MWW3 BLENDED WITH PREVIOUS/OFFICIAL FORECAST FOR WAVE PARAMETERS. HIGH CONFIDENCE. A SURFACE TROUGH EXTENDS FROM THE FLORIDA PANHANDLE ACROSS THE NORTH GULF WATERS TO NEAR 28N91W GENERATING SCATTERED SHOWERS AND TSTMS. GUSTY WINDS CAN BE EXPECTED WITH THIS ACTIVITY. THE TROUGH IS FORECAST TO SINK SOUTHWARD INTO THE CENTRAL WATERS TODAY...THEN WILL REMAIN NEARLY STATIONARY ON SAT AND LIFT NORTHWARD ON SUN. MARINE GUIDANCE SUGGESTS INCREASING SOUTHWESTERLY WINDS OF 20-25 KT ON THE SOUTH SIDE OF THE TROUGH BY SAT...ESPECIALLY OVER THE NE GULF WATERS. EXPECT ALSO BUILDING SEAS OF 6-7 FT WITH THESE WIND SPEEDS. AN INVERTED THERMAL TROUGH WILL DEVELOP EACH NIGHT OVER THE YUCATAN PENINSULA AND MOVE NW DURING LATE NIGHT THROUGH THE EARLY MORNING HOURS BEFORE DISSIPATING OVER THE SW GULF DURING THE LATE MORNING HOURS. MAINLY FRESH N-NE WINDS AND SEAS OF 4-5 FT WILL BE ASSOCIATED WITH THIS TROUGH. WINDS MAY BRIEFLY INCREASE TO 25 KT BY MON NIGHT. THE REMAINDER OF THE GULF REGION IS UNDER THE INFLUENCE OF A WEAK RIDGE PRODUCING MAINLY GENTLE TO MODERATE WINDS AND SEAS GENERALLY UNDER 4 FT. THE RIDGE IS EXPECTED TO BUILD BACK ACROSS THE AREA BY EARLY NEXT WEEK. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS/OFFICIAL FORECAST FOR WINDS. LATEST MWW3 BLENDED WITH PREVIOUS/OFFICIAL FORECAST FOR WAVE PARAMETERS. HIGH CONFIDENCE. THE 0200 UTC ASCAT PASS SHOWED FRESH TO STRONG WINDS OF 20-25 KT ACROSS THE SOUTH-CENTRAL CARIBBEAN MAINLY FROM 11N-14N BETWEEN 73W-78W. THE SAME ASCAT PASS SHOWED A LARGE AREA OF MOSTLY FRESH NE WINDS OVER MUCH OF THE CENTRAL CARIBBEAN S OF 16N. FRESH WINDS ARE ALSO NOTED PER SCATTEROMETER DATA ACROSS THE GULF OF HONDURAS. MAINLY FRESH TRADES WILL CONTINUE OVER THE CENTRAL CARIBBEAN THROUGH THE PERIOD WITH POCKETS OF STRONG NE TRADES NEAR THE COAST OF COLOMBIA THROUGH SAT. BY SAT NIGHT INTO SUN...EXPECT TRADE WINDS OF 25-30 KT ACROSS THE SOUTH CENTRAL CARIBBEAN AND BUILDING SEAS OF 10-12 FT. THESE MARINE CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE REMAINDER OF THE FORECAST PERIOD AS HIGH PRES BUILDS BACK N OF AREA. A TROPICAL WAVE NEAR 75W WILL MOVE ACROSS THE REMAINDER OF THE CENTRAL CARIBBEAN TODAY...THEN ACROSS THE WESTERN CARIBBEAN FRI NIGHT THROUGH SUN...REACHING THE YUCATAN PENINSULA SUN NIGHT. ANOTHER TROPICAL WAVE CURRENTLY OVER THE CENTRAL TROPICAL ATLC WILL APPROACH 55W LATE ON SAT...AND MOVE ACROSS THE EASTERN CARIBBEAN ON MON. LOOKING AHEAD...A BROAD LOW PRESSURE LOCATED A FEW HUNDRED MILES SW OF THE CAPE VERDE ISLANDS CONTINUES TO PRODUCE DISORGANIZED SHOWERS AND TSTMS AND HAS THE POTENTIAL FOR SOME SLOW DEVELOPMENT INTO EARLY NEXT WEEK AS IT MOVES IN A GENERAL WESTWARD TRACK. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS/OFFICIAL FORECAST FOR WINDS. LATEST MWW3 BLENDED WITH PREVIOUS/OFFICIAL FORECAST FOR WAVE PARAMETERS. HIGH CONFIDENCE. THE ATLANTIC RIDGE IS BUILDING BACK ACROSS THE SW N ATLC AS THE LOW PRES WITH THE ASSOCIATED TRAILING TROUGH PREVIOUSLY LOCATED OVER THE NW WATERS MOVES N OF AREA. THE RIDGE AXIS IS NOW ALONG 29N. PRES GRADIENT BETWEEN THE RIDGE AND A COLD FRONT APPROACHING THE ATLANTIC SEA BOARD WILL PRODUCE AN AREA OF SOUTHWESTERLY WINDS IN THE 20-25 KT RANGE ACROSS PARTS OF THE FORECAST ZONES AMZ111 AND AMZ113 THROUGH SUN. THE RIDGE WILL REMAIN IN PLACE THROUGHOUT THE REMAINDER OF THE FORECAST PERIOD. SCATTEROMETER DATA INDICATE FRESH TO STRONG WINDS OVER THE S WATERS JUST N OF HISPANIOLA...INCLUDING THE WINDWARD PASSAGE. FRESH TRADES WILL DEVELOP ALONG THE N COAST OF HISPANIOLA EACH NIGHT THROUGH TUE NIGHT. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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 GR. NATIONAL HURRICANE CENTER.