000 AGXX40 KNHC 120826 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 426 AM EDT Wed Apr 12 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... High pressure ridge persists across the nrn Gulf extending from the W Atlc WSW to SE Texas. A large cluster of deep convection occurring ahead of a cold front stalled across srn Texas has diminished in recent hours. Strong SE inflow into this convection reached 25 kt prior to 06Z and briefly kicked up seas across S Texas coastal waters to 6-9 ft, with winds and seas both having since subsided. Moderate to fresh E to SE winds prevail across all but NE portions, except for enhanced NE winds associated with Yucatan thermal trough shifting W across the Bay of Campeche. Seas are generally 4-6 ft across all but NE portions. Fresh to strong Ely flow through the Straits likely yielding seas 6-8 ft where wind is blowing against the FL Current. Ridging is expected to continue across the nrn Gulf through the weekend. A piece of llvl vorticity associated with central Atlc developing low has peeled off past 48 hrs and now moving into S FL and will produce weather as it shifts wwd and into the SE Gulf next 48 hrs. A modest wind surge will accompany this feature and maintain fresh to strong Ely winds and rough seas across the Straits and SE portions through early Thu. Otherwise, little change expected across the basin through Fri. A frontal system moving into the central U.S. Fri-Sat will induce SE return flow across the NW Gulf over the weekend. Meanwhile a new front and associated high pres will sink S across the W Atlc and freshen Ely winds through the Straits again through early Mon. The Yucatan thermal trough will dominate the daily cycle across the S central and SW gulf through the period. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... The gradient remains weak over the Ern Carib as troughing persists from the NE Carib waters N into the Atlc waters between PR and Bermuda. Latest data depicts fresh to strong northeast winds in the lee of Cuba and through Windward Passage, where seas are likely 5-7 ft. Moderate to fresh NE to ENE winds prevail elsewhere W of 70W, with nocturnal peak in winds to around 25 kt now setting up along the Colombian coast. Only modest changes in overall conditions expected next 24-48 hrs as a broad sfc low develops in associated with troffing N of PR and winds across the Bahamas weaken slightly and veer N to NNE. This to weaken the flow across Cuba and through the Windward Psg through late Thu but with nocturnal pulsing Thu night yielding 20 kt in lee of Cuba and Windward Psg. Same to be expected with winds off of Colombia. Developing sfc low to be kicked out to the NE and into central Atlc Fri to Sat with new front sinking into SW Atlc waters and post frontal high pres building across the region of 20N to freshen flow across NW portions through the weekend, and bring a return to fresh to strong trades across the entire central Carib by Sat night. Associated swell from front will impact tropical Atlc waters and NE Carib passages early next week with large long period Nly swell. ...SW N ATLANTIC INCLUDING THE BAHAMAS... Complex evolution of developing low pressure N of Puerto Rico continues this morning, with GFS having begun to trend closer to ECMWF but still shearing out too fast Fri. High pres remains centered across W Atlc with ridge WSW to Ga and across nrn Gulf of Mexico. Old frontal boundary remains draped across nrn periphery of developing sfc low near 25N765W. As mentioned above, piece of vorticity from this system 36 hrs ago has sheared off to the W and moving across the NW Bahamas and into S Fl attm with scattered shallow cnvtn and leading edge of another 20+ kt wind surge. 00-01Z ASCAT passes depicted a broad area of 20-25 kt winds N of the low and frontal system, generally from 26-30N where seas are building to around 10 ft. Models suggest winds here could yield pockets of 25-30 kt and are included in grids and far NE zone through tonight. Little change in forecast reasoning and have continued to follow ECMWF closely, with developing low to oscillate cyclonically next 24-36 hrs as mid- upper trough cutting off attm is then ejected to ENE Fri ahead of approaching upper trough sweeping through the region, supporting the sfc low with it. Strong high pres and new frontal boundary will drop quickly into the region behind this exiting low over the weekend to tighten pres gradient across the entire area and gradually shifting S of 25N by Sun night. Fresh to strong NE to E winds with wind swell producing seas 6-9 ft will otherwise dominate waters W of 70W through Fri. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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.