000 AGXX40 KNHC 091806 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 206 PM EDT Tue May 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... High pressure of 1020 mb located over the SE CONUS dominates the Gulf region, producing a gentle to moderate anticyclonic flow across the forecast waters. Latest buoy and altimeter data show relatively low seas throughout, with seas in the range of 1 to 3 ft over the eastern half of the Gulf waters, and 3 to 5 ft seas over the western half of the area. Seas are in the range of 5 to 6 ft over the eastern part of the Bay of Campeche due to the presence of fresh to strong winds associated with a thermal trough. This feature will move offshore the Yucatan Peninsula and across the SW Gulf at night and into the morning hours through Friday. A surge of fresh to locally strong easterly winds and seas in the 6 to 7 ft range will accompany this trough. A high pressure center will remain over the NE Gulf through Thursday night, with the associated gradient continuing to support moderate to fresh southeast winds over the western Gulf. The high pressure will then shift to SE of the Gulf on Friday in response to a weak cold front forecast to reach the far western Gulf at that time. The front is then forecast to reach a position from the NE Gulf to inland far southern Texas on Saturday. Weak high pressure will build in behind the front, with gentle to moderate northerly winds expected over the western half of the Gulf by late on Saturday, and gentle to moderate south to southwest elsewhere. Seas will be rather low at that time, with wave guidance suggesting 2 to 3 ft across the entire Gulf region. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... Mainly moderate to locally fresh trades prevail over the central and eastern Caribbean per scatterometer data and ship and buoy observations. Seas are generally under 6 ft across the entire basin. Fresh to locally strong NE winds are noted in the lee of eastern Cuba, and across the Windward Passage. These marine conditions are forecast to persist over the next 24-36 hours. High pressure north of area and low pressure near the coast of Colombia associated with the monsoon trough will support moderate to locally fresh trade winds over the central and eastern Caribbean, and Tropical N Atlantic forecast waters through the forecast period. Seas of 6 to 7 ft in northeast swell dominate the majority of the Tropical N Atlantic zones, however, wave model guidance suggests that the next set of long-period northeast swell will arrive into the eastern sections of the Tropical N Atlantic on Thursday and persist through Friday night with resultant combined wave heights maxing out to around 8 to 9 ft. ...SW N ATLANTIC INCLUDING THE BAHAMAS... A weakening frontal boundary extends from from 31N62W to 25N68W to 20N72W. The band of scattered showers and isolated thunderstorms associated with this front have moved to the east of 65W. However, the southern end of the band is still affecting the SE waters. Gentle northwest winds and seas in the range of 3 to 5 ft are noted behind the front. Moderate to fresh winds are ahead of the front, but mainly north of 25N. Farther west, a frontal trough persists and extends from 31N72W to 27.5N80W. A narrow line of clouds defines the trough on visible satellite imagery. Light winds and smooth seas area near the trough axis. A weak surface trough is analyzed from 25N65W to 18N67W. This feature will shift eastward reaching Puerto Rico on Wednesday, the US/UK Virgin Islands on Thursday, and the northern Leeward Islands by Friday with no significant impacts on winds and seas. The remainder of the area is under the influence of a ridge anchored by a 1020 mb high over the SE CONUS. A ridge will dominate the forecast waters much of the forecast period. A couple of cold fronts are expected to brush the far northern waters, one on Thursday and the second one on Friday. These fronts will be preceded by moderate to fresh southwest to west winds and building seas of 5-6 ft. Seas elsewhere will change little through the forecast period. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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 GR. National Hurricane Center.