000 AGXX40 KNHC 210750 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 350 AM EDT THU APR 21 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: BLEND OF THE 00Z GFS WITH PREVIOUS OFFICIAL FOR WINDS. PREVIOUS OFFICIAL WAVE FORECAST BLENDED WITH 00Z WAVEWATCH AND NWPS FOR WAVES. HIGH CONFIDENCE FOR WINDS AND WAVES. MEDIUM CONFIDENCE FOR CONVECTION. HIGH PRESSURE OVER THE SE UNITED STATES WILL SLOWLY DRIFT EASTWARD OVER THE WESTERN ATLC THROUGH THURSDAY...MAINTAINING MODERATE TO LOCALLY FRESH E TO SE WINDS OVER THE GULF BASIN. MODELS CONTINUE TO FORECAST A COLD FRONT TO REACH THE NORTHERN GULF COAST ON FRIDAY...BUT WILL MAKE LITTLE PROGRESS SOUTHWARD UNTIL THE TROUGH SUPPORTING THE FRONT REACHES THE EASTERN UNITED STATES AND WEAK RIDGING BUILDS OVER THE NW GULF FRIDAY NIGHT. BY THAT TIME THE SOUTHERNMOST EXTENT OF THE COLD FRONT WILL HAVE REACHED THE NE GULF. THE TROUGH SUPPORTING THE FRONT WILL THEN AMPLIFY OVER THE WESTERN ATLANTIC WHICH WILL ALLOW THE FRONT TO PROGRESS FARTHER SE OVER FL AND POINTS EAST. THE RIDGE THAT BUILDS OVER THE NW GULF FRI NIGHT WILL SLOWLY SLIDE EAST OVER THE WEEKEND...SUPPORTING LIGHT TO MODERATE ANTICYCLONIC WINDS OVER THE NORTHERN GULF...AND MODERATE TO FRESH NE TO E WINDS OVER THE SOUTHERN GULF. THE MAIN UNCERTAINTY DURING THIS TIME PERIOD IS CONVECTION...WITH PERIODS OF SHOWERS AND THUNDERSTORMS EXPECTED OVER THE W AND NW GULF TODAY...SPREADING EAST ACROSS THE NORTHERN GULF AHEAD OF THE COLD FRONT FRIDAY AND NE GULF FRIDAY NIGHT. CURRENT GFS IS MORE ROBUST WITH CONVECTION AS COMPARED TO THE ECMWF AND NAM...WHICH ONLY SHOWS ISOLATED CONVECTION OVER THE BASIN THROUGH THE PERIOD. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: BLEND OF THE 00Z GFS WITH PREVIOUS OFFICIAL FOR WINDS. PREVIOUS OFFICIAL WAVE FORECAST BLENDED WITH 00Z WAVEWATCH AND NWPS FOR WAVES. HIGH CONFIDENCE. THE TIGHT PRESSURE GRADIENT OVER THE NORTHERN CARIBBEAN BETWEEN RIDGING OVER THE SOUTHEASTERN UNITED STATES AND LOWER PRESSURES OVER SOUTH AMERICA WILL CONTINUE TO SUPPORT PERIODS OF FRESH TO STRONG NE WINDS THROUGH THE WINDWARD PASSAGE AND APPROACHES...AS WELL AS S OF HISPANIOLA THROUGH FRIDAY. SEAS TO 9 FT WILL OCCUR OVER THE N CENTRAL CARIBBEAN ASSOCIATED WITH THE PULSES OF STRONG WINDS S OF HISPANIOLA. THE HIGH PRESSURE RIDGE WILL MIGRATE EAST OVER BERMUDA THURSDAY NIGHT AND FRIDAY BEFORE REACHING THE CENTRAL ATLANTIC OVER THE WEEKEND. AS THIS TRANSITION OCCURS...TRADE WIND FLOW WILL DIMINISH TO MODERATE TO FRESH OVER THE CARIBBEAN BASIN. N TO NW SWELL GENERATED BY A FAST MOVING FRONTAL SYSTEM AND ASSOCIATED LOW WELL NORTH OF THE AREA WILL PROPAGATE OVER THE ATLANTIC ZONES FRIDAY THROUGH SUNDAY WITH SEAS REACHING AS HIGH AS 8 FT ACROSS THE EASTERN PORTIONS OF THE ATLANTIC ZONES SUNDAY. AMPLE LOW AND MID LEVEL MOISTURE CONTINUES TO SUPPORT SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS EAST OF 80W OVER THE BASIN. MODELS CONTINUE TO FORECAST A SURFACE TROUGH TO EFFECT THE NORTHERN LEEWARD ISLANDS FOR THE NEXT FEW DAYS WITH ENHANCED SHOWER ACTIVITY. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: BLEND OF THE 00Z GFS WITH PREVIOUS OFFICIAL FOR WINDS. PREVIOUS OFFICIAL WAVE FORECAST BLENDED WITH 00Z WAVEWATCH AND NWPS FOR WAVES. MEDIUM CONFIDENCE. STATIONARY FRONT EXTENDING FROM SOUTH CAROLINA COAST SE TO 27N71W WITH A FAST MOVING COLD FRONT FROM 27N71W EAST ACROSS THE CENTRAL ATLANTIC. HIGH PRESSURE IS CENTERED OVER THE SOUTHEASTERN UNITED STATES. MODELS CONTINUE TO FORECAST SWELL TO 10 FT GENERATED BY STRONG NORTHERLY WINDS BEHIND THE COLD FRONT TO AFFECT THE NORTHEASTERN CORNER OF OUR ZONES TODAY...WITH SWELL OF 6 TO 7 FEET AFFECTING MOST WATERS NE OF THE BAHAMAS THURSDAY AND FRIDAY. THE AREA OF HIGH PRESSURE WILL MIGRATE EAST ACROSS BERMUDA THEN SE OVER THE CENTRAL ATLC WHILE WEAKENING FRIDAY THROUGH SUNDAY. A NEW COLD FRONT AND PRE-FRONTAL TROUGH IS FORECAST TO MOVE OVER THE NW WATERS ON SATURDAY WITH MODELS HINTING AT A GOOD CHANCE FOR CONVECTION ACROSS THE BAHAMAS AND POINTS NORTHWARD OVER THE WEEKEND AS THE FRONT MOVES EASTWARD. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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 LATTO. NATIONAL HURRICANE CENTER.