000 AGXX40 KNHC 221847 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 247 PM EDT Wed Mar 22 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 1021 MB high is analyzed near 26.5N90W and will meander over the n-central gulf today then shift n into Louisiana and become absorbed into large shifting ridge across the ern US. Moderate anticyclonic winds currently prevail around periphery of high with peak seas of 4-5 ft across SW and NW portions. A thermal trough will develop late each afternoon over the Yucatan Peninsula, and shift w across the waters generally to s of 22N between 90W and 93W during the overnight hours, and gradually lose identity along about 94W late each morning. Expect a ne-e-se 20-25 kt wind shift along the trough axis, with seas building briefly 6-7 ft each night. Model guidance in good agreement on development of strong winds across most of basin Thu night through Fri night as new cold front moves S across W Atlc and FL and weakly backdoor into NE portions. Strong high pres behind front to induce E to SE winds 20-25 kt with potential for small areas to 30 kt NW waters. Seas to build 8-10 ft Fri NW waters. High to then open up across full basin as deep layered low moves slowly across central US Fri night through the weekend. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... Old frontal boundary from Windward Psg NE into central Atlc drifting NNW today and continues to block ridge from influencing E half of basin. Modest area of fresh NE winds were depicted by 14-15Z ASCAT pass and 15-20 kt through Windward Psg. Fresh NE winds in lee of Cuba have diminished today, but will redevelop tonight with the strong ne pulses then continuing through Thu. Cold front to move SSE across Atlc waters next 72 hrs and being to gradually tighten pres gradient across W half of basin beginning Thu night into the weekend. However, some uncertainty remains during the weekend with the development of a llvl inverted trough N to NE of Hispaniola. Sharpness of trough will influence wind direction across NW Carib and strength of flow through Windward Psg and in lee of Cuba. Winds have veered SE across NE Carib and adjacent Atlc in response to NW drifting frontal boundary, while moderate to fresh E to ESE trades prevail across the tropical N Atlc waters. NNW swell moving through regional Atlc waters and NE Carib passages today and still about 2 ft above wave guidance. ...SW N ATLANTIC INCLUDING THE BAHAMAS... Old frontal boundary from Windward Psg to near 24N60W has begun to drift NNW today, while slowly digging mid to upper trough across Ern Gulf and NW Carib acting to significantly enhance cnvtn along boundary. Nly swell across the region is fading today but still producing 8-9 ft seas far SE waters. Next front dropping into NW waters attm with fresh to strong SW flow just ahead of it. Models in good agreement with front moving SSE and laying down along about 23N Fri to Sat while current old boundary aids in leaving an inverted trough from nrn Hispaniola NE into Atlc ahead of the approaching front. Strong pres gradient between trough and strong high behind the front to generate large area of strong winds behind front and bridging over it to inverted trough. Large area of 30 kt winds depicted by models Fri through Sat between 60W and 75W and am gradually leaning toward a gale warning across this area. Models not currently showing gales at 10m but with such a large area of 30 kt winds, it would appear that gales would be likely. Seas to build 10-15 ft across this zone and will hit the SE half of Bahamas with battering waves. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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.