000 AXNT20 KNHC 051038 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Mon Oct 5 2020 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 32N. 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... Tropical Storm Gamma is centered is near 22.8N 87.4W at 05/0600 UTC or 160 nm ENE of Progreso Mexico, moving W at 2 kt. Estimated minimum central pressure is 999 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Gamma has an exposed center currently, with most of the shower and thunderstorm activity sheared well to the northeast of the center due to strong S to SE winds aloft. Moderate to strong convection is observed over the eastern central Gulf from 25N to 27N between 85W and 88W. A recent scatterometer satellite pass showed a band of tropical storm force winds within 150 nm in the northern quadrant of the storm, with generally fresh to occasionally strong winds on the southern portion of Gamma, over the north coast of Yucatan. The long fetch of the persistent strong NE winds to the north of the center is supporting seas to as high as 17 ft in the northwest quadrant of Gamma. Gamma is expected to through mid week as it parallels the coast of northwest Yucatan, briefly going inland Wed, on the Campeche coast before turning northward again toward the south- central Gulf. Gamma will become a minor low center by Thu on the southern periphery of a possible Hurricane Twenty-six expected to be moving across the central Gulf at that time. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT5.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMAT5.shtml for more details. Tropical Depression Twenty-Six is centered near 16.9N 77.8W at 05/0600 UTC or 80 nm SW of Kingston Jamaica moving WNW at 8 kt. Estimated minimum central pressure is 1006 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Numerous showers and thunderstorms are noted within 180 nm in the south semicircle of Twenty-six this morning. The depression is expected to continue to move WNW today, and strengthen to a tropical storm just west of Jamaica by this afternoon. The storm will then continue to move through the northwest Caribbean, passing over Grand Cayman tonight, then strengthen further through early Tue as it approaches western Cuba. Twenty-six is forecast to become a hurricane late Tue as it moves through the Yucatan Channel and crosses over the western tip of Cuba, then continue toward the north-central Gulf of Mexico by late in the week. Heavy rainfall will affect portions of Jamaica, the Cayman Islands, and western Cuba during the next few days. This rainfall could lead to significant flash flooding and mudslides. Dangerous surf is likely over parts of western Cuba and the Isle of Youth. Interests in the northern Gulf should monitor monitor the progress of the system and check for updates to the forecast during the week. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT1.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMAT1.shtml for more details. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 50W from 20N southward, moving W at 10-15 kt. Scattered moderate convection is east of this wave from 16N-19N between 46W-48W. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through coastal sections of southern Mauritania to 1010 mb low pressure centered near 17N17W, to 09N27W to 06N35W. The intertropical convergence zone continues from 06N35W to the coast of Guyana near 06N58W. No significant showers or thunderstorms are noted at this time. GULF OF MEXICO... Please see the Special Features section above for information on T.S. Gamma, and T.D. Twenty-six. Outside of the area of showers and thunderstorms over the east central Gulf, a fairly dry pattern is in place with no significant convection noted, to include over T.S. Gamma. Fresh to strong NE to E winds are noted over most of the Gulf outside of the main area of Gamma, with 6 to 9 ft seas. Light to gentle breezes are noted over the far northwest Gulf, with 3 to 5 ft seas. The development and track of both T.S. Gamma and T.D. Twenty-six will be the main influences on the forecast for the Gulf of Mexico through late week, as described above. CARIBBEAN SEA... Please see Special Features section for information on Tropical Depression Twenty-Six. The monsoon trough extends across the southwest Caribbean from 11N80W to the coast of Costa Rica near 10N83W. Other than the area of showers and thunderstorms noted above associated with T.D. Twenty-six, thunderstorms are active off the Guajira Peninsula in Colombia, and in the Gulf of Venezuela. Thunderstorms are also active off Cabo Gracias a Dios in eastern Honduras. A few showers may be active over the northern Windward Islands as well. Fresh to strong west winds with 4 to 6 ft seas are noted north of Roatan and east of Belize. Strong SE winds and 8 to 10 ft seas are active between Jamaica and the southern peninsula of Haiti. Elsewhere, gentle to moderate winds and 3 to 5 ft are noted over the Caribbean. Beyond the impacts of T.D. Twenty-six mentioned above, the pattern will gradually shift to moderate to fresh E to SE winds across the basin, with the strongest winds over the south-central Caribbean by late in the week. ATLANTIC OCEAN... A stationary front extends near the coast of Florida from 31N76W to near Cape Canaveral, Florida at 28N81W. No significant showers or thunderstorms are noted near the front. Moderate NE winds are north of the front with light to gentle SSE winds ahead of it. Farther east, 1021 mb high pressure is analyzed near 32N62W, and east of that a trough is analyzed along 55W from 23N to 30N. No significant showers are noted near the trough, nor are there any winds greater than 20 kt, but swell to 8 ft lingers along the trough axis, a legacy of fresh to strong winds along the trough several days ago. The main influence is 1029 mb high pressure centered near 38N33W west of the Azores. This is supporting generally moderate trade winds over the waters east of 50W, except for fresh to strong winds and seas to 9 ft off North Africa. For the forecast, SE winds will increase slightly across the Bahamas by Tue as T.D. Twenty-six strengthens south of Cuba. Reinforcing front will move off Florida and stall by mid week, before moving northward again as a warm front. $$ Christensen