000 AGXX40 KNHC 280830 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 430 AM EDT Wed Jun 28 2017 Marine Weather Discussion for the Gulf of Mexico, Caribbean Sea, and Tropical North Atlantic from 07N to 19N between 55W and 64W and the Southwest North Atlantic including the Bahamas ...GULF OF MEXICO... A weak stationary front continues across the NE Gulf coastal waters this afternoon, and has moved little in past 24 hours. Expect the boundary to drift S across the FL coastal waters through this afternoon while gradually becoming diffuse. Elsewhere gentle to moderate gentle E to SE winds prevail across most of the basin. Mild seas prevail at 3-4 ft W half and 1-3 ft E half. A low level trough has shifted NW across the W half of basin past few days and has ignited active cnvtn across the NW waters tonight but has recently diminished in coverage. The trough is expected to drift slowly NW today and inland across S TX and NE Mexico tonight. Winds will veer slightly today with Sly return flow spreading into TX and LA coasts tonight after trough moves inland. A frontal system moving into the Great Plains will combine with high pres moving to the Ern seaboard to produce moderate to fresh return flow across most of the basin tonight and then gradually strengthen to fresh to locally strong Thu night into Fri as the frontal system moves SE into the TX Panhandle. Seas to increase to 4-6 ft during this time, with Yucatan diurnal thermal trough yielding strong winds across N and NW peninsula waters, with potential to increase seas briefly to 7 ft. Somewhat similar conditions to continue into the weekend as a weak high settles into the far NE Gulf and the frontal boundary retreats Nwd into the Central Plains. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... Modest Atlc ridge continues from central Atlc SW to just E of the NW Bahamas and is yielding a modest pres gradient across the basin this morning. A series of tropical waves moving W through the basin are separated by SAL and fair weather in between. A tropical wave is approaching Central America along 81W/82W, with the best moisture behind the wave and producing widely sct cnvtn invof of wave. Moderate E to SE winds and seas 4-7 ft are occurring N of 13N and just behind wave axis. The next broad tropical wave is moving across the Tropical N Atlc waters attm, and has a secondary perturbation trailing invof 56W. Active cnvtn continues with this wave and has lifted to along 15N with and ahead of axis and will shift across the Windwards today. A broad area of SAL and some zones of significant dust are moving wwd across the E Carib to the W and NW of the wave and spread across the top of this wave to just beyond 70W and E across much of the MDR. ENE winds around 20 kt have accompanied this wave with E to SE winds around 15 kt behind it. An area of 6-8 ft seas also depicted by recent altimeter passes within the fresh ENE winds and will shift W and hit the islands today. A slight SE shift of Atlc ridge past 24 hours will tighten pres gradient slightly across basin to yield peak nocturnal winds near 30 kt off of Colombia early this morning and again tonight before gradient weakens as second tropical wave moves across central portions and expands fresh to strong winds across N central portions. Atlc ridge to nose back into FL and NE Gulf of Mexico by the end of the week, and behind this second wave, in order to bring a return to strong trades across much of S central Carib on Friday and Saturday. ..SW N ATLANTIC INCLUDING THE BAHAMAS... Atlc ridge extends from 1027 mb high near 37N47W to just E of the NW Bahamas, while weak frontal boundary persists across N FL and the extreme NW corner of FA. This is yielding moderate to fresh E trades S of 23N E of 69W and moderate SE winds W of there around the periphery of the ridge, becoming light to moderate S to SW NE of the Bahamas. Seas are around 4 ft across the SE waters in zone of trades and 2-3 ft elsewhere. The frontal boundary will drift SE to along about 30N today before lifting N of area tonight through Thu. This will maintain these generally mild winds and seas across the waters through the end of the week. As high pres shift E off mid Atlc coasts and into the W Atlc tonight and Thu, the diurnal thermals along the N coastal zone of Hispaniola will expand to 22N with seas pushing 8 ft there during the evening. Expect SAL and hazy conditions to prevail across the E and central Carib and tropical N Atlc waters N of the tropical wave moving into Windward Islands. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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.nhc.noaa.gov/marine $$ .Forecaster Stripling. National Hurricane Center.