000 AGXX40 KNHC 172000 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 400 PM EDT Tue Apr 17 2018 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... 1022 mb high pressure is situated over the north central Gulf just to the southeast of Louisiana. This high controls the wind regime throughout the basin as noted by the anticyclonic nature of the wind direction s being reported by the buoy observations. The gradient between the high pressure and lower pressure over the southern Plains is supporting fresh southeast return flow over the NW Gulf off the Texas coast. Moderate N to NE flow is also noted across the far southeast Gulf into the Straits of Florida. This flow is following in the wake of a cold front that exited the southeast Gulf yesterday. A recent scatterometer satellite pass also indicated a small area of fresh to strong northerly winds off west coast of Yucatan, where a nocturnal trough is forming along the coast. Buoy and altimeter data show seas in the range of 3 to 5 ft, except for higher seas in the 5 to 7 ft within the fresh southeast return flow over the NW Gulf, and much lower seas of 1 to 2 ft in the far NE Gulf. The forecast remains on track through the upcoming period. High pressure over the north central Gulf will shift eastward to the NE Gulf Wed and weaken in response to a cold front that will move over the northern gulf waters Thu. The front will stall from southwest Florida to south Texas Fri, before lifting back north as a warm front Sat ahead of yet another cold front that will move across Texas. This front is expected to move across the NW Gulf, and reach from near the western Florida panhandle to the SW Gulf Sun night. A warm front will extend out ahead this front across the eastern gulf. The gradient between it and high pres over the eastern U.S. should support fresh to locally strong E to SE winds over much of the NE Gulf Sun. In addition, an anticipated challenge with this next frontal system will be with respect to precipitation as surface low pres may track across the northern gulf waters, and while at the same time low pres aloft tracks over the southern U.S. starting with day 5. This scenario is likely to increase the instability already associated with the frontal system. A potential for widespread rain, showers, and thunderstorms may be in the offering for much of the northern gulf beginning Sun. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... A weakening frontal boundary extends from eastern Cuba to central Honduras. The earlier fresh N to NE winds have diminished to moderate winds and seas in and near the Gulf of Honduras have lowered slightly since this morning. A line of showers remains active along and near the boundary. Farther south, strong trade winds are along the coast of Colombia. Farther east, a surface trough is near 65W. Scattered showers and isolated thunderstorms are east of this trough to the north of 16N, including the Leeward Islands. This activity is expected to gradually diminish through this evening as the trough pulls farther west and away from the eastern Caribbean. Meanwhile, NE to E swell to 8 ft is still present in the tropical Atlantic waters east of the Windward Islands. For the forecast, the frontal boundary will dissipate through Wed. A trough over the eastern Caribbean will move through Hispaniola and dissipate through mid week. Ridging north of the region will maintain fresh to strong winds off Colombia through late in the week, expanding from the south central into the southwest Caribbean late Wed through late Fri as high pressure builds north of the area, then diminishing in areal coverage Sat through Sun as the ridge weakens. ...SW N ATLANTIC INCLUDING THE BAHAMAS... A cold front extends from just west of Bermuda to eastern Cuba. Scattered showers and a few thunderstorms are active along the frontal boundary. Strong SW winds are noted north of 29N within 120 nm east of the front. Strong NW winds are present north of 30N off northeast Florida, related a reinforcing trough moving off the Carolina coast toward the front. Seas are 8 to 12ft north of 30N west of 68W. Elsewhere over open waters, seas are 5 to 7 ft. The front will slow down as it reaches from near 29N65W to 26N70W where it will become stationary to eastern Cuba by early Wed. The cold front portion will become stationary during Wed, before the entire front dissipates early on Thu. The frontal remnants will lift northward through Fri ahead of the next cold front. This next cold front will move off the northeast Florida coast late Thu, reach from Bermuda to south Florida by late Fri, before stalling from 25N65W to the Straits of Florida by late Sat. The gradient will tighten between the front and high pres that builds eastward over the northern portion on Sat night into Sun allowing for east winds to increase over much of the western section of the area. Widespread rain along with scattered showers and isolated thunderstorms may impact the far NW waters beginning on Sun. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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 Aguirre. National Hurricane Center.