000 AGXX40 KNHC 231834 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 234 PM EDT Thu Mar 23 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 1022 MB surface high is analyzed near 28N91W this morning and will shift N and inland today and become absorbed in strong ridge building toward the region from the NE. Ensuing pressure gradient will tighten across the entire gulf this evening through Fri as this ridge builds across the basin and pushes a dry backdoor front across NE portions of gulf. Fresh to strong easterly breezes will develop tonight with an embedded swath of 30 kt se winds...and seas to 9-10 ft...near 27N96W near sunrise on Fri. The pressure gradient will relax on Fri as the parent high shifts E into the Atlc with fresh se to s flow forecast everywhere by Sat morning. A moderate to locally fresh easterly breeze forecast across the southern gulf waters on Sun. Small patches of strong southerly flow is forecast along the coast of Central Mexico on Sun afternoon, as well as developing along the n coast of the Yucatan Peninsula on Sun evening. The pressure gradient should relax some more on Mon, with only a fresh breeze expected along the n coast of the Yucatan on Mon evening. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... Fresh NE winds continue in the lee of Cuba and have even backed slightly as cold front approaches region from the N and inverted trough sharpens N of Hispaniola. Fresh to strong NE winds will developing this evening in and downstream of the Windward Passage on Thu. Expect this strong ne flow to continue across the n-central and the nw Caribbean on Fri. The pressure gradient is forecast to relax on Sat, but still expect strong ne pulses to the lee of Cuba on Sat and Sun nights. Large n swell will reach the NE Caribbean Passages late Fri night, and continue through early Sun before subsiding. Strong ne nocturnal winds expected within 90 nm of the nw coast of Colombia tonight. Fresh trades will continue across the tropical waters e of the Antilles Leewards with seas generally remaining 6-8 ft next 48 hours in mix of NNW swell and ENE tradewind swell. Development of low pres N of Hispaniola over the weekend and its motion will strongly influence winds across Nrn waters Sat night and beyond. ...SW N ATLANTIC INCLUDING THE BAHAMAS... Old frontal boundary nearly stationary from 26.5N65W TO THE SE BAHAMAS will meander today as strong cold front sinks SSE across NW half of area today. Morning ASCAT pass showed N to NE winds 20-25 kt behind front from 30N to to front and SW to FL E coast. Seas behind front in strongest swath of winds NE of Bahamas are about 2-3 ft above WW3 guidance and 1-2 ft above ECWave. Front will continue SSE and nearly merge with old boundary through Fri night-Sat...laying nearly W to E along 24N. Meanwhile, models in agreement that a sfc low will develop along inverted trough currently SE of old boundary, and N of Hispaniola, but location and shape of low still evolving with each new run. Have followed the GEFS for low placement which is good average between global models. Strong to near gale force post-frontal ne winds will spread se across the entire area with 10 to 15 ft seas propagating S across the waters E of the Bahamas late tonight into Fri. Models indicate large area of 25-30 kt winds and frequent gusts to gale force would seem likely, but have yet to issue Gale Warning. Pres gradient will tighten further across N semicircle of low and at that time it appears sustained gales are more likely, Sat evening through Sun. Have been hesitant to issue gale with 5 degree difference in low location between models, but 12Z runs coming in now a bit closer, and will consider for 18-21Z updates. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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.