000 AXNT20 KNHC 201018 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Sun Oct 20 2024 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 0600 UTC surface analysis and satellite imagery through 1000 UTC. ...SPECIAL FEATURES... Hurricane Oscar is centered near 21.1N 73.1W at 20/0900 UTC over Great Inagua Island, and is moving west at 10 kt. Estimated minimum central pressure is 988 mb. Maximum sustained wind speed is 70 kt with gusts to 85 kt. Oscar remains a very small system, with hurricane-force winds extending only out to 5 nm from the center, and tropical storm force winds reach as far as 40 nm from the center. Numerous showers and thunderstorms extend as far as 90 nm from the center. Oscar will move toward the coast of eastern Cuba this afternoon, move inland and weaken to a tropical storm over eastern Cuba through late Mon. Oscar will then move northward toward and cross the southern Bahamas again, through Tue night, then continue to move to the NE before dissipating by early Thu. Oscar is expected to produce a dangerous storm surge on portions of the southeastern Bahamas this morning, especially Great Inagua Island, and along the north shore of Cuba later this afternoon and evening. Heavy rainfall from Oscar will lead to areas of flash flooding along with possible mudslides across portions of eastern Cuba, especially within the Sierra Maestra, through Tue. Tropical Depression Nadine is inland near 16.8N 91.8W at 20/0900 UTC or 70 nm E of Tuxtla Gutierrez Mexico, moving WSW at 12 kt. Estimated minimum central pressure is 1006 mb. Maximum sustained wind speed is 25 kt with gusts to 35 kt. Numerous moderate to isolated strong convection is noted over Belize, northern Guatemala and the Yucatan Peninsula. On the forecast track, Nadine is expected to move across northern Guatemala and southern Mexico through today. Gradual weakening is expected, and Nadine is forecast to dissipate on Sunday. Widespread rainfall amounts of 4 to 8 inches, with isolated areas of 12 inches, are expected across northern Belize, northern Guatemala, and southern Mexican states from Quintana Roo westward to Veracruz and Oaxaca through Tue. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website - https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml, the latest NHC Forecasts/Advisories and Public Advisories for Oscar and Nadine at www.hurricanes.gov for more details. ...TROPICAL WAVES... A tropical wave is along 34W from 20N southward, moving west at around 10 to 15 kt. Scattered moderate convection is noted from 18N to 20N between 33W and 36W. A second tropical wave is moving across the central Caribbean. Its axis extends from Dominican Republic to northwest Colombia. No significant convection is depicted at this time in reaction to this tropical wave, although scattered overnight thunderstorms are active over nearby Lake Maracaibo. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic near 19N16W and extends southwestward to 07N25W. The ITCZ runs from 11N45W to 08N57W. Aside for the convection associated with the tropical wave, scattered moderate convection is noted from 08N to 12N between 40W and 50W. ...GULF OF MEXICO... The pressure gradient between tropical cyclone Nadine to the south and strong high pressure over the eastern United States supports fresh to strong NE to E winds across most of the Gulf waters, including the Straits of Florida and the Yucatan Channel. Seas are in general 5 to 8 ft, except 8 to 12 ft over the SE and central Gulf. While, seas of 8 to 11 feet prevail over the Straits of Florida. Outer bands, with embedded showers and thunderstorms, associated with the cyclonic circulation of Nadine are reaching the northern Yucatan Peninsula and regional waters and the central and eastern portions of Bay of Campeche and the central Gulf. For the forecast, fresh to strong NE winds and rough seas will continue to affect much of the basin into Mon as strong high pressure builds over the southeast United States. Looking ahead, winds and seas will then diminish across the basin through mid week as the high pressure shifts eastward and weakens. ...CARIBBEAN SEA... Scattered showers and thunderstorms on the outer edges of Hurricane Oscar are impacting the northern entrance to the Windward Passage. Scattered showers and thunderstorms are active along the monsoon trough north of eastern Panama. Fresh to strong winds and rough seas persist near the Yucatan Channel, between high pressure north of the area and T.D. Nadine, currently weakening over southern Mexico and drifting westward. Gentle to moderate winds and moderate seas persist elsewhere across the Caribbean. For the forecast, the winds and seas over the northwest Caribbean will diminish through Mon night as Nadine dissipates and the high pressure weakens and shifts eastward. Mostly gentle to moderate breezes and slight to moderate seas will persist across the basin thereafter through Thu night. ...ATLANTIC OCEAN... Please see the Special Features section for information on Hurricane Oscar. A cold front enters the region near 31N54W and extends SW to 25N66W where it becomes a dissipating stationary front that extends into western Cuba. A few showers and thunderstorms are near and ahead of the front but mainly north of 28N. Strong high pressure over the southeast United States in the wake of the front is supporting fresh to strong NE winds mainly west of 65W, accompanied by combined seas of 8 to 11 ft with a component of northerly swell. Aside for Hurricane Oscar, the remainder of the Atlantic forecast waters is under the influence of a ridge, anchored by a 1024 mb high pressure situated west of the Madeira Islands. Moderate to fresh winds and 5 to 8 ft seas are noted south of the high pressure, and off the coast of northwest Africa. For the forecast west of 55W, outside of the impacts of Oscar described above, a cold front from 31N54W to 25N65W will drift eastward today, then weaken to a trough through the early part of the week. Fresh to strong winds and rough seas will prevail west of the front through Tue. $$ Christensen