000 AGXX40 KNHC 080800 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 400 AM EDT Mon May 8 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 1018 mb located over the north-central Gulf near 27N89W dominates the region, with associated gentle to moderate anticyclonic flow across the forecast waters. Seas have lowered even some more in the eastern Gulf, where recent altimeter data and buoy reports shows seas there in the range of 1 to 2 ft. Seas are 2 to 3 ft over the central Gulf and 3 to 4 ft in the western Gulf from 20N to 28N west of 94W. The high pressure is forecast to slowly shift eastward reaching the NE Gulf waters on Friday allowing for moderate to fresh southeast winds to develop over the western Gulf and continue through Thursday. Fair conditions are expected to prevail over the basin under the control of the high pressure. A thermal trough will begin to move offshore the Yucatan Peninsula and move across the SW Gulf at night and into the morning hours. A surge of fresh to locally strong easterly winds and seas in the 6 to 7 ft range will accompany this trough. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... A weakening stationary front extending from eastern Cuba to just northeast of NE Honduras will dissipate by this evening. Gentle to moderate NE to E winds are occurring west of the front and also elsewhere west of about 79W per latest Ascat data and current buoy observations, with seas in the 2 to 4 ft range. A pocket of slightly higher seas in the 3 to 5 ft range is located from 13N to 16N between 79W and 82W. The combination of the front and a weakening upper trough advancing eastward across the central Caribbean is resulting in ample deep layer moisture. This has created plenty of atmospheric instability over the much of the central portions of the Caribbean, and also over the eastern sections of the western Caribbean during the past few days. Scattered showers and isolated thunderstorms are noted between 70W and 80W, including much of Hispaniola, the extreme eastern tip of Cuba and eastern Jamaica. This activity is not as widespread as yesterday. It will continue to push eastward through this afternoon while decreasing. On the other hand, scattered showers and thunderstorms over the far SW Caribbean and along the coasts of Costa Rica and Panama are associated with the eastern Pacific monsoon trough that extends into those geographic areas of the Caribbean basin. This activity is forecast to increase through the morning, and remain quite active through the end of the week as low pressure expected to form along the trough will be the impetus to further prolong this activity. Mainly gentle to moderate trades prevail over the remainder of the Sea, with the exception of moderate to fresh trades across the eastern Caribbean per latest Ascat data and recent observations from buoy 42060 located at 16N63W. Seas are generally under 6 ft across the basin. Seas over the remainder of the basin are in the 4 to 5 ft range, except for slightly lower seas of 3 to 4 ft over the northeast portion near the Leeward Islands. High pressure over the central Atlantic and low pressure near the coast of Colombia associated with the monsoon trough and forecast low pressure as stated above 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 9 ft. This may possibly be a little higher if in deed the swell arrives with more energy than anticipated. ...SW N ATLANTIC INCLUDING THE BAHAMAS... As of 06Z the cold front of the previous days has become stationary along a position from 31N66W to 25N70W and to eastern Cuba. Mainly gentle to moderate west to northwest winds and seas in the range of 4 to 6 ft are west of the front to the Bahamas and north of 27N west of the front to 78W. Lower seas of 1 to 3 ft are confined to west of the Bahamas, and north of 27N west of 78W. A lingering pocket of combined seas to 8 ft in mixed east and northwest swell is north of 30N between 65W and 67W. This swell is rapidly decaying, and is forecast to dissipate just before daybreak today. East of the front, south to southwest winds of 10 to 15 kt are noted north of 25N, and east to southeast 10 to 15 kt winds are south of 25N east of the front. Seas are 4 to 5 ft east and southeast of the front, with the exception of the lingering mixed swell. The stationary front will weaken today and undergo dissipating through Tuesday. A couple of ship observations along with a partial Ascat pass indicate that a weak trough has formed to the southeast of the front from near 23N70W to the coast of northwest Haiti. This feature is progged by the models to shift eastward reaching the vicinity of Puerto Rico Tuesday night into Wednesday, and the Leeward Islands Thursday through Friday. A weak cold front is analyzed at 06Z from 31N72W to inland just south of Jacksonville. This front is observed in satellite imagery to be a dry front as dry air aloft is present as seen on water vapor imagery. The front will weaken further as it moves over the north central portions of the basin through Tuesday night, with little impacts to winds and seas. Weak high pressure will build across the area in the wake of the aforementioned fronts through Wednesday night. The high pressure will become more of a ridge axis roughly along 26N/27N on Thursday as it is forced south-southeastward through Friday in response to a couple of fronts that brush the far northern waters. These fronts will be preceded by moderate to fresh southwest to west winds along with seas of 5 to 8 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 Aguirre. National Hurricane Center.