000 AGXX40 KNHC 040501 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 101 AM EDT Fri Aug 4 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 surface trough extending across the NW Gulf will continue weaken and drift N and inland SW Louisiana and NE Texas this evening as an E to W ridge builds from Tampa Bay to NE Texas where it will meander through Sun. Expect considerable convection over the northern gulf waters well into tonight. A thermal trough will develop over the Yucatan Peninsula each evening, move slowly westward during the overnight hours, and dissipate over the SW Gulf each morning. Expect a moderate to locally fresh NE-E-SE wind shift, and 2-4 ft seas, along this trough through Mon, then guidance is suggesting a tighter pressure gradient that will support a fresh to locally strong wind shift. This tightening of the gradient will be associated with a tropical low expected to soon develop along a tropical wave over the NW Caribbean, with this system moving across the Yucatan Peninsula early next week most, likely accompanied by large rainfall accumulations. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... A broad tropical wave is currently analyzed along 68W with several cyclonic mid level swirls noted along the wave axis. Considerable convection is currently enhanced E of wave, mainly to the N of 12N across the Lesser Antilles. Thus, convection will be depicted in the weather grids for the next several days along the forecast positions of the wave. Scatterometer data already indicates strong E winds, and a recent altimeter pass detected seas to 9-1/2 ft. With the large areas of convection forecast, expect strong to near gale force winds to accompany the wave, with these conditions W of the Caribbean late Tue. Fresh to locally strong trades are expected along the NW coast of Colombia through mid morning today. A strong tropical low associated with a tropical wave will approach 55W late Tue night with favorable environment conditions for tropical cyclone formation. ...SW N ATLANTIC INCLUDING THE BAHAMAS... A surface high is expected to develop today near 28N71W along an E to W ridge. The high will drift slowly N through Tue with a ridge extending WSW and later W to NE Florida. Moderate to locally fresh SW flow expected N of the ridge through early Sun, then light southerly flow is expected. The northern extent of a tropical wave is currently along 68N. Expect fresh to strong E trades across the waters S of 23N through early Sat, then strong E trades just along the N coast of Hispaniola during the late afternoons into early evenings. A strong tropical low associated with a tropical wave will approach 55W late Tue night with favorable environment conditions for tropical cyclone formation. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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 Nelson. National Hurricane Center.