000 AXNT20 KNHC 150502 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Sun Oct 15 2023 Tropical Weather Discussion for North America, Central America Gulf of Mexico, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 0000 UTC surface analysis and satellite imagery through 0450 UTC. ...SPECIAL FEATURES... Tropical Depression Sean is centered near 16.9N 45.5W at 15/0300 UTC or 1010 nm E of the northern Leeward Islands, moving NW at 7 kt. Estimated minimum central pressure is 1008 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Peak seas are currently 10 ft. Scattered moderate to strong convection is noted within 75 nm of the center in the SE semicircle and 45 nm NW semicircle. A turn toward the west-northwest is expected early this morning, followed by a turn toward the west by early Monday. Sean could become a remnant low today and then is forecast to dissipate on Monday. Please read the latest High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest Sean NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Eastern Tropical Atlantic (AL94) Gale Warning: A 1009 mb low pressure is centered near 9.5N32.5W. Scattered moderate to isolated strong convection is noted from 06N to 13N between 32W and 37W. The convection associated with this system has not become any better organized Sat afternoon or evening. However, environmental conditions are forecast to become more conducive for further development, and a tropical depression or tropical storm is likely to form within the next couple of days while the system moves westward or west-northwestward across the central and western tropical Atlantic. This system has a high chance of development within 48 hours. In anticipation of this system developing, a gale warning has been issued. Seas will build to over 12 ft by Mon morning, when the system is centered in the vicinity of 10.5N38W. Additional information on this system, including the gale warning, can be found in the High Seas Forecast at https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and in the Tropical Weather Outlook at www.hurricanes.gov Central Atlantic Large Swell: A cold front extends from 31N43W to 27N48W to 25N53W. Strong to near gale force SW winds are occurring within 360 nm east of the cold front, north of 27N. Seas of 12 to 18 ft are currently affecting waters north of 27N between 38W and 48W. A recent satellite altimeter pass from 15/0200 UTC showed seas of 16 to 18 ft occurring near 30N-31N between 41W-42W. Seas of 12 ft or greater will continue to affect the waters north of 27N between 35W and 45W through today before subsiding by this evening. ...TROPICAL WAVES... An eastern Atlantic Ocean tropical wave has an axis along 23/24W from 03N to 18N, moving W at 10 kt. Scattered moderate isolated strong convection is noted within 270 nm W and within 150 nm E of the wave axis from 04.5N to 16.5N. ...MONSOON TROUGH/ITCZ... The monsoon trough extends off the coast of Guinea near 11N15W to 09N26W to AL94 to 09.5N37W. Scattered moderate convection is between the coast of Africa and 20W from 03.5N to 10N. ...GULF OF MEXICO... As of 0300 UTC, a cold front extends from the eastern Florida Panhandle near 30N84W to 25N92W to the coast of Mexico north of Tampico, near 23N98W. Fresh northerly winds are NW of the front. A pre-frontal surface trough extends from Key Largo, FL to 22N94W. Isolated moderate to strong convection is near and just N of the surface trough between 88W and 93W. Additional moderate convection is seen near the coast of southern Mexico near Veracruz. Gentle winds are over the SE Gulf, south of 26N and east of 90W, where seas are 1 to 3 ft. In the western Gulf, fresh northerly winds are occurring also to the south of the front, extending to 20N. Seas of 5 to 6 ft prevail over the western Gulf, while 3 to 4 ft seas prevail over the NE Gulf. For the forecast, the cold front will continue moving SE across the basin through the weekend, reaching the Yucatan Channel and Straits of Florida late tonight or early Mon morning. Fresh to locally strong winds and rough seas will persist behind the front through Mon night. Winds and seas will diminish through mid-week as high pressure builds over the northern Gulf in the wake of the front. ...CARIBBEAN SEA... Deep-layered ridging extends across the Caribbean. Isolated to scattered thunderstorms are noted along the east Pacific monsoon trough and the Colombian coast, mainly south of 13N. Isolated thunderstorms are also seen over SW Haiti, as well as near the coastline of southern Belize to western Honduras. Otherwise, the rest of the basin remains quiet. The latest ASCAT satellite data shows gentle to moderate trade winds across the basin. Seas range from 2 to 4 ft across most of the basin. For the forecast, gentle to moderate breezes and slight seas will persist through late today. Winds and seas will increase over the far northwest Caribbean starting tonight following a cold front moving through the Yucatan Channel. The front will stall from central Cuba to Belize Mon, and dissipate into mid week. Fresh NE winds and moderate wave heights will persist over the northwest Caribbean through late Wed as high pressure builds over the area. Looking ahead, there is a high chance that a tropical depression or storm will develop over the Atlantic during the next several days, possibly bringing winds to gale force and very rough seas to the tropical Atlantic waters east of the Leeward Islands by late Thu. ...ATLANTIC OCEAN... Please read the Special Features section on T.D. Sean, the Gale Warning for AL94, and the large swell area north of 27N between 35W and 48W. A weak cold front extends from 31N74W to 29N74W. Fresh to strong W winds and 6 to 8 ft seas prevail W of the front. A surface trough extends from the NW Bahamas to Key Largo, FL. Isolated thunderstorms are along and just S of the trough. Over the western Atlantic, winds are generally moderate or stronger north of 23.5N and west of 68W. Winds are light to gentle elsewhere west of 60W. A cold front extends from 31N43W to 27N48W to 25N53W, stationary to 25N59W. A warm front continues from 25N59W to 28N70W to 31N71.5W. Scattered moderate isolated strong convection is along and within 120 nm SE of the cold front. Isolated showers and tstorms are south of the stationary and warm fronts. Winds are fresh or stronger within about 480 nm east of the cold front, mainly north of 24N and west of 30W. Seas of 8 ft or greater in association with the frontal system still extend as far west as 57W and as far south as 23N. Mainly gentle winds prevail from 10N to 31N between 50W and 60W. Winds are mostly gentle over the NE part of the area, north of 20N and east of 30W, due to ridging. However, scattered showers are found north of 28N across this area. For the forecast W of 55W, expect fresh to strong winds over waters north of 30N and west of 70W today associated with a cold front that will move off the northeast Florida coast early this morning. A reinforcing trough will maintain fresh NW winds off northeast Florida Mon. The front will slow down and weaken from Bermuda to central Cuba by early Tue, then stall and dissipate from 31N60W through eastern Cuba by mid week. $$ Hagen