000 AGXX40 KNHC 100800 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 400 AM EDT Wed May 10 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 1019 mb has shifted to the NE Gulf near 27.5N85W per the 0316Z Ascat pass. This feature remains the main weather feature controlling the weather regime across the Gulf. The latest scatterometer passes along with current observations from buoys and oil platforms reveal mostly moderate anticyclonic flow over Gulf, with the exception over the NE Gulf where light to gentle winds are noted around the immediate high center. The buoy observations along with recent altimeter data show relatively low seas, with seas in the range of 1 to 3 ft to the northeast of a line from the Texas/Louisiana border to just west of the western tip of Cuba. Seas in the range of 3 to 5 ft are to the west of this same line, with the exception of a a pocket of higher seas in the 5 to 7 ft range as a result of prolonged southeast winds across a large fetch area being over the far western Gulf from 24N to 28N west of 95W. A small area of 5 to 6 ft seas has materialize over the far eastern part of the Bay of Campeche, and just north of the NW Yucatan Peninsula due to fresh to strong northeast to east winds associated with a thermal trough. This feature will continue doing its routine thing of moving offshore the Yucatan Peninsula and across the SW Gulf at night and into the morning hours through Friday. The high pressure center over the NE Gulf will slowly shift eastward through Thursday, with the associated gradient continuing to support moderate to fresh southeast winds over the western Gulf. The high pressure will then move inland north/central Florida on Friday as it loses its identity, and while at the same time a ridge forms near 26N, and a weak cold front moves offshore the Texas coast. The ridge will be shunted to the southeast and east of the Gulf through Saturday in response to the cold front advancing across the forecast waters. The front is forecast to reach a position from the Big Bend area of Florida to the SW Gulf on Saturday afternoon, then weaken over the SE Gulf on Sunday. Models indicate that 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 1 to 3 ft across the Gulf. ...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 latest Ascat passes and ship and buoy observations. Fresh to locally strong northeast winds are noted in the lee of eastern Cuba. The fresh to strong northeast winds earlier noted through Windward Passage have diminished to the fresh range. Both recent altimeter data and current buoy observations report seas in the 3 to 5 ft across the entire basin, except for lower seas of 1 to 2 ft south and southwest of a line from 19N88W to 16N82W to 11N82W to 11N77W to 12N71W, and also within 60 nm of the lee of Cuba. 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. The fresh to locally strong northeast winds in the lee of Cuba will diminish by around 12Z this morning. Fresh to strong northeast winds are expected through the Windward Passage beginning this evening and into late tonight before diminishing to the fresh category near daybreak on Thursday. 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 to east swell will arrive into the far eastern sections of the Tropical N Atlantic tonight, with resultant combined wave heights maxing out to around 8 to 9 ft. This set of swell will continue to propagate through the waters south of about 15N while decaying into Friday. Active weather in the form of scattered showers and thunderstorms will continue over much of the SW Caribbean Sea through the period as the eastern segment of the eastern Pacific monsoon trough remains entrenched there, and while at the same time low pressure develops along it from time to time. Numerous showers and scattered thunderstorms currently affecting the northeast portions of the Caribbean Sea in association with a surface trough that is along 66W north of 16N will remain quite active through Thursday afternoon, while decreasing in coverage as the mid/upper level trough axis pushes to the east of the Caribbean. This activity is already impacting the northwest portion of the Tropical N Atlantic waters, and is expected to continue through Friday evening. ...SW N ATLANTIC INCLUDING THE BAHAMAS... The recent weakening frontal boundary of the past several days has dissipated, and generally weak high pressure is established across the area as the culprit 1018 mb high center is analyzed at 30N75W. A rather pronounced surface trough is analyzed at 06Z along a position from 24N66W south 21N to over Puerto Rico. Current buoy and ship observations show gentle to moderate anticyclonic flow around the higher center, with the moderate winds confined to the far southern waters west of 71W. The buoys along with recent altimeter passes reveal seas in the range of 3 to 5 ft northeast and east of the Bahamas, and lower seas of 1 to 2 ft west of the Bahamas as well as north of the Bahamas west of 78W. The surface trough will continue to shift eastward reaching the Virgin Islands on Thursday, and the northern Leeward Islands by Friday with no significant impacts on winds and seas. A series of of cold fronts are expected to quickly brush the far northern waters during the next few days. The first one will pass through Wednesday night into Thursday, the second one on Friday and the third one appears to be the strongest according to the latest model runs. This one will move over the far northwest waters on Saturday night into Sunday, and over the north/central waters and northwest portion of zone AMZ115 on Sunday night. This front will be preceded by fresh to strong southwest winds and seas building to the range of 8 to 10 ft. Mainly fresh northwest winds will follow in behind the front, with seas of around 6 to 8 ft. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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.