000 AGXX40 KNHC 141724 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 124 PM EDT Fri Apr 14 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 thermal trough will develop late each afternoon over the Yucatan Peninsula, and shift w across the southwestern waters, generally to s of 23N between 90W and 93W, during the overnight hours, and gradually lose identity along about 94W late each morning. Expect a ne-e-se 15-20 kt wind shift along the trough axis, with seas building to 6 ft, except fresh to strong conditions are forecast along the trough on Sat, Sun and Mon evenings. Otherwise, a ridge extends w across the northern coastal plains with weak n to s orientated surface troughs passing w under the ridge across the n-central gulf waters accompanied by showers and occasionally a tstm. Moderate to locally fresh easterlies are maintaining 3-5 ft seas. A tightening pressure gradient will increase the low level flow across the eastern gulf to a fresh to locally strong breeze tonight, and throughout Sat, with seas building to 8 ft in the Gulf Stream. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... Strong ne nocturnal winds, and 7-9 ft seas, are expected within 90 nm of the nw coast of Colombia each night through Mon. A tightening pressure gradient will support strong trades and 5-7 ft seas across the central Caribbean waters on Sat night. Moderate to fresh ne winds across the nw and n-central Caribbean will increase to a fresh to locally strong breeze tonight and again on Sat night with strongest winds to the lee of Cuba, in and downstream of the Windward Passage and to the lee the Dominican Republic with seas building to 8 ft in these areas. Large n swell in the form of 7-8 ft seas will arrive at the ne Caribbean passages on Mon, and spread s across the tropical waters e of the Leewards on Mon night, spreading across the Windward's on Tue and reaching the n coast of S America on Wed. ...SW N ATLANTIC INCLUDING THE BAHAMAS... The pressure gradient between a surface low pressure over the se waters a surface high over the se Conus is supporting fresh to locally strong ne flow, and 8-11 ft seas, across the waters ne of the Bahamas, and moderate to fresh ne flow across the Bahamas and Fl Straits, with 4-7 ft in the open waters. The low is forecast to shift to near 24N65W tonight as a second low forms near 29N56W. The southern low will weaken to an open trough just n of Puerto Rico late Sat, then drift w and gradually dissipate through Sun. Strong ne to e flow forecast s of 27N w of 65W on Sat, with the gradient relaxing on Sun, with associated winds at 20 kt or less by late Sun night. The northern low will shift ne of the area on Sat with strong to near gale northerly flow developing across the discussion waters from 26N to 31N between 55W and 65W. Conditions will improve on Sun night and Mon. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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.