000 AGXX40 KNHC 260757 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 357 AM EDT THU MAY 26 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. ----------------------------------------------------------------- PREVIOUS DISCUSSION... ...GULF OF MEXICO... MODEL PREFERENCE: PREVIOUS OFFICIAL FORECAST BLENDED WITH THE GFS AND ECMWF FOR WINDS. PREVIOUS OFFICIAL FORECAST BLENDED WITH GFS-BASED WAVEWATCH3 FOR WAVES. HIGH CONFIDENCE. A SURFACE RIDGE EXTENDS FROM THE NE GULF TO NEAR THE TEXAS-MEXICO BORDER. A MODERATE NE-SW PRESSURE GRADIENT OVER THE GULF IS PRODUCING E TO SE WINDS UP TO FRESH BREEZE CONDITIONS. TONIGHT THROUGH SATURDAY NIGHT WILL SEE AN ACCENTUATION OF WINDS TO STRONG BREEZE CONDITIONS IN THE SW GULF IN ASSOCIATION WITH THE DIURNAL THERMAL TROUGH THAT ORIGINATES DAILY OVER THE YUCATAN. THE SOUTHEAST RETURN FLOW WILL ALSO REACH STRONG BREEZE CONDITIONS IN THE NORTHWEST GULF OF MEXICO FRIDAY AND SATURDAY. SUNDAY AND MONDAY WILL HAVE QUIESCENT CONDITIONS OVER THE ENTIRE GULF. WAVE HEIGHTS WILL REMAIN BELOW 8 FEET FOR THE NEXT SEVERAL DAYS. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: PREVIOUS OFFICIAL FORECAST BLENDED WITH THE GFS AND ECMWF FOR WINDS. PREVIOUS OFFICIAL FORECAST BLENDED WITH GFS-BASED WAVEWATCH3 FOR WAVES. HIGH CONFIDENCE. A MODERATE N-S PRESSURE GRADIENT ACROSS THE CARIBBEAN IS PRODUCING WINDS UP TO STRONG BREEZE CONDITIONS OVER THE SOUTH CENTRAL CARIBBEAN. AN 0246Z ASCAT SCATTEROMETER PASS MEASURED E WINDS UP TO 25 KT JUST NORTH OF COLOMBIA. THESE WINDS WILL GRADUALLY DIMINISH TO FRESH BREEZE OR WEAKER BY FRIDAY AND REMAIN WEAK THROUGH MONDAY. SHIP WDC7379 REPORTED 11 FT SEAS AT 06Z AND A TOPEX PASS SHOWED VALUES UP TO 12 FT IN THE WEST CENTRAL CARIBBEAN. THESE WERE HIGHER THAN EXPECTED...THOUGH WITH THE SURFACE WINDS RELAXING... WAVE HEIGHTS ACROSS THE CARIBBEAN SHOULD DROP BELOW 8 FT BY TONIGHT. THERE ARE NO SIGNIFICANT LONG PERIOD SWELL AFFECTING THE TROPICAL NORTH ATLANTIC THROUGH THE NEXT SEVERAL DAYS. ONE TROPICAL WAVE IS PRESENT THIS MORNING WITH WAVE AXIS NEAR 65W. HOWEVER...THERE ARE NO SIGNIFICANT WINDS OR WAVES WITH THIS WEAK FEATURE. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: PREVIOUS OFFICIAL FORECAST BLENDED WITH THE GFS AND ECMWF FOR WINDS. PREVIOUS OFFICIAL FORECAST BLENDED WITH GFS-BASED WAVEWATCH3 FOR WAVES. MODERATE CONFIDENCE. A 1016 MB LOW IS CENTERED NEAR 26N68W WITH A SURFACE TROUGH EXTENDING NNE-SSW THROUGH THE LOW. THE 0108Z AND 0156Z ASCAT SCATTEROMETER PASSES INDICATED THAT PEAK WINDS AROUND 25 KT WERE OCCURRING IN THE EASTERN SEMICIRCLE. THESE WINDS WERE SUBSTANTIALLY HIGHER THAN ANY MODEL ANTICIPATED...SO THE WIND GRIDS WERE ADJUSTED UPWARD AT THE INITIAL TIME AS WELL AS IN THE NEXT DAY. THE SCATTEROMETER DATA AND LAST-LIGHT VISIBLE IMAGERY WERE ALSO SUGGESTIVE THAT THE LOW DID HAVE A CLOSED LOW-LEVEL CIRCULATION. THE SYSTEM HAS HAD PERSISTENT DEEP CONVECTION NOW FOR ABOUT 15 HOURS...WHICH IS AIDED BY THE DIVERGENT UPPER-LEVEL FLOW INDUCED BY AN UPPER TROUGH WEST OF THE LOW. THE GLOBAL MODELS ARE SUPPORTIVE FOR GRADUAL DEVELOPMENT AND THE SPECIAL TROPICAL WEATHER OUTLOOK ISSUED LAST NIGHT AT 2340Z INDICATED A 30 PERCENT CHANCE OF GENESIS DURING THE NEXT 48 HOURS AND A 60 PERCENT CHANCE OF GENESIS OVER THE NEXT FIVE DAYS. WITH GRADUAL DEVELOPMENT ANTICIPATED CURRENTLY...PEAK WINDS NEAR THE NORTHERN PORTION OF THE SURFACE TROUGH ARE INDICATED TO REMAIN AT STRONG BREEZE TO NEAR GALE CONDITIONS AS IT MOVES SLOWLY TOWARD THE NORTHWEST. WAVE HEIGHTS ARE ANTICIPATED TO REACH 8 FEET TONIGHT IN THE EASTERN SEMICIRCLE OF THE LOW. ELSEWHERE TRADEWINDS WILL REMAIN AS MODERATE TO FRESH BREEZE THROUGH MONDAY. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS II COLLABORATION CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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 LANDSEA. NATIONAL HURRICANE CENTER.