000 AGXX40 KNHC 090833 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 433 AM EDT Sun Apr 9 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 1020 mb high is centered along the coast of the FL panhandle this morning and extends a ridge weakly into SW portions. Recent scatterometer data showed gentle to moderate anticyclonic winds around the periphery of the basin, with ship and buoy obs suggesting seas generally 3 to 5 ft across the SW half and 1-2 ft NE half. Moderate to fresh southeast return flow has set up over the NW Gulf and will continue today through late Mon ahead of a cold front advancing in the southern Plains. Fresh easterly flow is expected to develop in the E Gulf tonight through Tue as the front stalls across central Texas. Fresh to locally strong easterly winds associated with the Yucatan trough will develop and move west in the Bay of Campeche each night through Wednesday. Moderate trades are expected elsewhere across the basin through Thursday as the high shifts NE and into the W Atlc offshore of the Carolinas. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... Ill defined frontal boundary is washing out from Ern coast of Cuba to near NE coast of Honduras, with high pres behind front centered across the NE Gulf of Mexico. Recent scatterometer data showed moderate NE winds NW of the front to about 85W, and fresh E trades across the SE Carib S of 13.5N, and fresh NE to N winds along the Colombian Basin. Wave model output appears to verify well with limited obs and altimeter data with seas 4-5 ft across NW portions outside of Gulf of Honduras and 5-7 ft across Colombian Basin. The front extends NE along the E coast of Cuba and across the Turks and Caicos and into the central Atlc, and is not expected to move much S of 22N next 24 hours. The boundary in the Carib will dissipate today while an inverted trough is expected to develop SE of the stalled front across the Atlantic between 60W and 70W. This to maintain a modest pressure gradient and gentle to moderate trade winds across most of the basin through Tuesday, with smaller than normal area of strong nocturnal trades off Colombia. As the high over the Gulf shift NE into the W Atlc Sun night and Mon a strong pressure gradient will develop between high pres to the north and the frontal remnants across the Atlc. This will create a broad swath of strong NE winds across the Atlc and Bahamas that will spill across Cuba to produce strong nocturnal winds in the lee of Cuba Sun, Mon and Tue nights to build seas to at least 6 ft each early morning. ...SW N ATLANTIC INCLUDING THE BAHAMAS... A weakening cold front nearly bisects the offshore zones from 31N60W across the Turks and Caicos to along the E coast of Cuba. near 21N75W. Recent ASCAT data and ship obs show moderate NE within about 120 nm NW of the front north of the southern Bahamas, and gentle to moderate winds elsewhere. 23Z altimeter data showed seas 6-8 ft between 24N and 26N within this swath of NE winds that likely extends NE behind the frontal boundary in mixed NW swell. The front will continue to weaken and stall W of 65W during the next 24-36 hours, and an inverted trough is expected to develop SE of the stalled front north of the islands between 60W and 70W. Models depicts a couple of weak llvl trofs moving across the SE waters that will eventually merge N of Puerto Rico. A strong pres gradient will develop between the stalled boundary and high pres shifting off mid Atlc coast to produce an elongated swath of NE winds that will affect much of the northwestern zones through Tue, including the Bahamas and Cuba. A surface low may try to develop within the inverted trough by mid week, and produce area of winds around 30 kt and seas 10-12 ft north of 25N between 62W and 75w. Fresh to strong NE winds and building seas will affect coast of southern Florida coast Sun night through late Wed, then diminish Thursday. Models continue to suggest that upper trough will pick up this broad weak llvl troffing SE of trof by mid week and drag it ENE, leaving a much more narrow zone of fresh to strong NE to E winds along the old boundary. Have trended latest forecast towards the EC beyond Wed. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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.