000 AGXX40 KNHC 061902 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 302 PM EDT THU AUG 6 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 A BROAD RIDGE EXTENDS FROM CENTRAL FLORIDA W-SW TO CENTRAL PORTIONS ALONG ABOUT 24N...A BIT S OF RECENT MODEL GUIDANCE. OBS SUGGEST ANTICYCLONIC FLOW PREVAILING AT 15 KT OR LESS...EXCEPT THROUGH STRAITS OF FL...WHERE RECENT 15Z ASCAT PASS SHOWED SMALL AREA OF 15-20 KT OFF NW CUBA. MAX SWH OBS AT 4 FT ACROSS SW PORTIONS AND ACROSS S TX COASTAL WATERS. LITTLE CHANGE IN RECENT FORECAST REASONING AS WEAK RIDGE WILL GENERALLY REMAIN IN PLACE WHILE DEEP LAYERED LOW DIGS FROM OHIO VALLEY SE INTO SE U.S. WITH SFC LOW SHIFTING E-NE OFF MID ATLC COAST AND DRAGGING FRONTAL TROUGH INTO FL PANHANDLE SAT AFTERNOON WHERE IT WILL MEANDER THROUGH MON BEFORE BEGINNING TO LIFT N MON NIGHT-TUE. GFS BRIEFLY FORECASTS WLY WINDS NEAR 20 KT FRI NIGHT IN ADVANCE OF BOUNDARY ACROSS NE COASTAL WATERS. MOISTURE AND MID TO UPPER DYNAMICS IN PLACE ACROSS NE PORTIONS FRI NIGHT THROUGH SUN FOR ACTIVE WEATHER...LIKELY TO OCCUR IN BANDS AND LINES. THE THERMAL TROUGH WILL DEVELOP EACH EVENING OVER THE YUCATAN PENINSULA AND MOVE NW DURING LATE NIGHT THROUGH EARLY MORNING HOURS BEFORE DISSIPATING OVER THE SW GULF DURING LATE MORNING HOURS. MODERATE TO FRESH WINDS AND SEAS OF 4-6 FT WILL BE ASSOCIATED WITH THIS TROUGH MAINLY IN THE LATE NIGHT AND EARLY MORNING HOURS. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: GFS-ECMWF CONSENSUS A MODEST NARROW RIDGE EXTENDS W-SW ACROSS NW HALF OF AREA AND INTO S CENTRAL FLORIDA...AND IS GRADUALLY SEPARATING FROM STRONG CENTRAL ATLC RIDGE BY TUTT LOW REFLECTION STRENGTHENING 55W-62W ATTM. RECENT SCAT PASSES SHOWED STRONG TRADES ACROSS S CENTRAL PORTIONS S OF 13.5N WITH 20 KT TRADE EXTENDING FROM THERE TO BARAHONA PENINSULA OF DOM REP. WINDS AND SEAS HAVE BEEN ON A SLOW DECREASING TREND THERE PAST 12 HOURS. TROPICAL LOW NEAR 13.5N54.5W THIS MORNING SHIFTING WNW AND WEAKENING AND EXPECTED TO OPEN UP INTO TROUGH THIS EVENING. OVERNIGHT SCAT AND ALTIMETER PASSES SUGGESTED WINDS 20-25 KT AND SEAS 6-8 IN N SEMICIRCLE...WHICH HAS DIMINISHED VERY SLIGHTLY TODAY. THIS FEATURE WILL MOVE WWD AND ACROSS ISLANDS NEXT 24 HRS. AGAIN...NO CHANGES IN GUIDANCE AND FORECAST REMAINS GENERALLY THE SAME. CENTRAL ATLC RIDGE TO SHIFT NE AND ASSOCIATED RIDGING ACROSS SW N ATLC TO WEAKEN THIS EVENING THROUGH EARLY SAT AND WEAKEN PRES GRADIENT ACROSS THE BASIN...AND STRONG TRADES ACROSS S CENTRAL PORTIONS TO SHRINK SIGNIFICANTLY. BLOCKING OF LLVL RIDGE BY TUTT TO LIFT OUT OF AREA LATE MON AND ALLOW ATLC RIDGE TO BEGIN TO BUILD INTO BAHAMAS BY TUE FOR GRADUALLY FRESHENING OF TRADES ACROSS BASIN MON NIGHT THROUGH MID WEEK. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: GLOBAL MODEL CONSENSUS ATLC RIDGE BEGIN BLOCK BY DEEPENING TUTT LOW REFLECTION ACROSS W CENTRAL ATLC...WITH WEAK HIGH PINCHING OFF NE OF BAHAMAS NEAR 28N73W AND YIELDING LIGHT TO GENTLE FLOW ACROSS MOST OF AREA...EXCEPT FOR MODERATE ENE TRADES SE BAHAMAS. SEAS LIKELY 5 FT OR LESS ACROSS THE AREA. THIS WEAK RIDGE TO REMAIN NEARLY STATIONARY OVER THE NEXT 24 HOURS BEFORE WEAK HIGH COLLAPSES AND FRONTAL TROUGH MENTIONED ABOVE SINKS INTO EXTREME NW PORTIONS SAT THROUGH MON...WITH SWLY FLOW AROUND 20 KT BRIEFLY DEVELOPING AHEAD OF IT SAT. THE RIDGE WILL BEGIN TO RE-ESTABLISH ACROSS THE AREA MON NIGHT OR TUE TO PRODUCE GENERALLY MODERATE SE TO S FLOW ACROSS MOST OF THE AREA. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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 STRIPLING. NATIONAL HURRICANE CENTER.