000 AGXX40 KNHC 180726 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 326 AM EDT Sun Jun 18 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 prevails over the Gulf waters. Latest satellite derived winds and seas along with ship, buoy, and CMAN data depict light to gentle winds over the eastern Gulf with gentle to moderate winds over the western Gulf. Seas are in the 1-2 ft range over the eastern Gulf and 2-4 ft over the western Gulf. A large cyclonic gyre continues to evolve over the northwest Caribbean and Central America. There remains considerable uncertainty with the overall structure, strength, and location of the feature as the forecast evolves into early next week. There still is a wide spread with respect to how models track this feature through next week. Will maintain continuity with previous forecast packages in keeping a general northwest track with this system from the NW Caribbean Sea to across the northern Yucatan peninsula tonight and into the south-central Gulf waters just northwest of the peninsula by Monday evening, and in a general northwestward direction through the upcoming week as depicted in the latest runs of the ECMWF and UKMET models, which have come into very close agreement in the forecast track of this system. There remains a high chance that this low will develop into a tropical cyclone over the next 5 days. Regardless of tropical cyclone development, this system will impact the area with strong winds and building seas likely over much of the Gulf early next week, accompanied by very active and widespread showers and thunderstorms. The rainfall associated to this system will also impact portions of Central America, the Yucatan Peninsula, Cuba, and Jamaica, with flash flooding and mudslides possible over prone areas. Expect winds and seas to begin to build over Yucatan Channel and far southeastern waters beginning on Sunday. Interests in the southern Gulf, and surrounding land masses, should monitor the Tropical Weather Outlook for the latest information on this evolving weather scenario. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... A large cyclonic gyre continues to develop over the northwest Caribbean waters and Central America. Very deep convection in large clusters is erupting over much of the NW Caribbean well to the east and northeast of an ill-defined cyclonic swirl near 18N87W. The Ascat pass from 0220Z last night revealed a large swath of strong to near gale northeast to southeast winds to the east of the low. This appears to depict a trough that extends northeastward from the low. Latest satellite derived winds and seas along with ship, buoy, and CMAN data depict fresh to strong winds over the northern waters south of eastern Cuba and Jamaica, fresh winds elsewhere over the Central Caribbean, and moderate to fresh winds over the remainder of the forecast waters. Seas are in the 6-8 ft range over the central Caribbean, and 4-6 ft over the remainder of the forecast waters. Strong to near gale winds will cover most of the northwest Caribbean through late Monday night as the broad low moves through the Yucatan peninsula. Seas will build to 8 to 14 ft, with highest seas in the Yucatan Channel. This will be accompanied by a large area of thunderstorms and squalls. This band of winds and seas will lift north of the area by the middle part of the upcoming week. There is currently a high chance that the low will develop into a tropical cyclone over the next 5 days. Regardless of tropical cyclone development, this system will impact the area with strong to near gale winds and building seas over the northwestern Caribbean into early next week, accompanied by very active and widespread weather. The rainfall associated to this system will also impact portions of Central America, the Yucatan Peninsula, Cuba, and Jamaica, with flash flooding and mudslides possible over prone areas. Interests in the western Caribbean, and surrounding land masses, should monitor the Tropical Weather Outlook for the latest information on this evolving weather scenario. Outside of this area, high pressure over the western Atlantic will support increasing trade winds and building seas over much of the central and eastern Caribbean early next week, and through the middle part of the week. By Thursday afternoon, a diminishing area of lingering strong southeast winds is expected over portions of the NW Caribbean, and small patches of strong east winds just south of Jamaica and the Dominican Republic. Seas of 8-10 ft are expected to linger over the central Caribbean on Thursday, but diminish to 8 ft during the afternoon. Seas of 8-9 ft will be over the NW Caribbean on Thursday. Further east, a pair of tropical waves are propagating through the Atlantic waters east of the Leeward Islands. The tropical waves will move across the tropical north Atlantic and eastern Caribbean forecast zones bringing an increase in winds and seas later this weekend into the middle of next week. ...SW N ATLANTIC INCLUDING THE BAHAMAS... High pressure prevails over the forecast waters. Latest satellite derived winds and seas along with ship, buoy, and CMAN data depict light to gentle winds over the northeast waters with gentle to moderate winds elsewhere. Seas are in the 3-4 ft range outside the Bahamas except for slightly higher seas of 4-5 ft seas south of about 22N, and lower seas of 1-2 ft west of the Bahamas. High pressure will prevail over the forecast waters through midweek. Winds are increasing over the southwest waters as the pressure gradient tightens between the ridge and the developing Central America gyre. These winds and seas are expected to decrease midweek. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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.