000 AXNT20 KNHC 042311 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Sun Oct 4 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 1800 UTC surface analysis and satellite imagery through 2215 UTC. ...SPECIAL FEATURES... Tropical Storm Gamma has stalled of the north coast of the Yucatan Peninsula this afternoon, near 22.4N 87.8W at 04/2100 UTC or 110 nm NE of Progreso Mexico. Estimated minimum central pressure is 997 mb. Maximum sustained wind speed is 50 kt with gusts to 60 kt. Numerous strong convection is noted within 150 nm N semicircle, with scattered moderate convection within 150 nm S semicircle. Showers and thunderstorms are also impacting portions of the SE Gulf of Mexico, the Florida Peninsula, far western Cuba, and the Yucatan Peninsula. Seas have built to 15 to 18 ft near and to the NW of the center of Gamma, in the south-central Gulf of Mexico, enhanced by a long fetch of persistent NE winds. Tropical Storm Gamma is expected to remain stationary into Mon, then begin to move slowly WSW Mon night and Tue. On the forecast track, Gamma will remain a tropical storm through mid-week, with its center remaining off the northern and western coasts of the Yucatan Peninsula. Gradual weakening is anticipated to begin later tonight or on Monday and continue into Tuesday. 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. The tropical wave in the central Caribbean has organized further this afternoon and is now considered a potential tropical cyclone. Potential Tropical Cyclone Twenty-Six is centered near 16.7N 76.6W at 04/2100 UTC or 80 nm S of Kingston Jamaica moving WNW at 9 kt. Estimated minimum central pressure is 1007 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Numerous moderate to isolated strong convection is located within about 210 nm SE semicircle from the center and 90 nm NW semicircle. A tropical depression is expected to form in the next day or two, and the system will Jamaica and the Cayman Islands Mon into Tue. Interests in these areas as well as western Cuba closely monitor the progress of this system, as Tropical Storm Warnings and Hurricane Watches have been issued. Locally heavy rainfall and gusty winds are also possible over portions of Hispaniola over the next few days. 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 WAVES... An Atlantic Ocean tropical wave is along 47W from 20N southward, moving W at 05-10 kt. A 1010 mb low is along the wave near 13N47W. Showers and thunderstorms previously associated with this wave have diminished, and there is no longer a chance of tropical development with this wave and low. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through coastal sections of Senegal near 14N17W to 07N24W to 05N38W. The ITCZ continues from 05N38W to 09N46W to the coast of French Guiana near 05N52W. Numerous moderate to isolated strong convection is located within 60 nm on both sides of the monsoon trough. GULF OF MEXICO... Please see the Special Features section above for information on T.S. Gamma. The portion of a stationary front that extends E into the Atlantic has now dissipated in the far eastern Gulf. Strong N winds encompass the bulk of the central Gulf of Mexico, with winds becoming less closer to the coasts. Away from the direct influence of Tropical Storm Gamma, seas average 4 to 7 ft. Tropical Storm Gamma is expected to meander off the N coast of the Yucatan Peninsula through Mon morning, and then begin a slow W to SW motion, reaching near 22.1N 88.6W Mon afternoon, near 21.3N 90.4W Tue afternoon, near 20.1N 91.4W Wed afternoon, and then near 21.0N 92.1W Thu afternoon, before beginning to drift slowly N through the end of the week. Newly classified Potential Tropical Cyclone TWENTY-SIX is located near 16.7N 76.6W 1007 mb at 2100 UTC moving WNW or 290 deg at 9 KT. Maximum sustained winds 30 kt gusts to 40 kt. This system is expected to become a Tropical Storm across the NW Caribbean Mon and then turn more NW and move across western Cuba Tue evening, exiting into the SE Gulf of Mexico as a hurricane early Wed morning before continuing off the the NW and reaching near 26.5N 90.3W Thu afternoon then towards the N central Gulf through Fri. CARIBBEAN SEA... Please see Special Features section for information on Potential Tropical Cyclone Twenty-Six. The monsoon trough extends across the southwest Caribbean from 12N78W to the coast of Costa Rica near 10N83W. Scattered moderate convection is over the Virgin Islands and N of Puerto Rico from 18N-20N between 63W-67W. Away from the potential tropical cyclone and Tropical Storm Gamma just NW of the Yucatan Channel, gentle to moderate trade winds prevail across most of the Caribbean, with some fresh to locally strong NW winds off the coast of Honduras. Seas average 4 to 7 ft. Newly classified Potential Tropical Cyclone TWENTY- SIX is located near 16.7N 76.6W 1007 mb at 2100 UTC moving WNW or 290 deg at 9 KT. Maximum sustained winds 30 kt gusts to 40 kt. This system will continue this general motion tonight and become better organized by Mon, reaching near 18.0N 79.1W Mon afternoon as a Tropical Storm, then move more NW and reach near 21.0N 82.8W Tue afternoon just below hurricane strength. TWENTY-SIX is then expected to move NW across western Cuba Tue evening and exit into the SE Gulf of Mexico as a hurricane early Wed morning before continuing off the the NW and towards the N central Gulf. Meanwhile, Tropical Storm Gamma will meander off the N coast of the Yucatan Peninsula tonight and Monday before moving SW and into the Bay of Campeche late Tue through Wed. ATLANTIC OCEAN... A stationary front extends from 31N79W to near Daytona Beach Florida. Convection previous associated with this front has ended. Another stationary front a bit farther east has dissipated. A surface trough is over the central Atlantic from 31N49W to 24N52W. Disorganized and scattered showers and thunderstorms are noted within about 120 nm either side of this trough. This trough is expected to move WSW at 10 kt over the next couple of days, and has a low chance of slow tropical development through mid- week, until the system encounters strong upper-level winds. A broad surface ridge extends from 1031 mb high near 39N37W west of the Azores to a secondary high pressure center of 1023 mb near 32N60W. To the south and west of this ridge, fresh to strong E winds are being supported off the north coast of Hispaniola. These winds will likely continue through tonight, before diminishing as the ridge weakens and slides east. The stationary front off Florida will dissipate tonight, but by Mon morning a cold front will move off the SE U.S. coast. This front will drift south through Tue then stall from 31N73W to near W Palm Beach Florida by mid week. In the eastern Atlantic, fresh to locally strong NE winds and seas to 9 ft are active off the African coast of Western Sahara and Mauritania. Elsewhere, generally moderate trade winds persist across the Atlantic with mostly 5 to 7 ft seas. $$ KONARIK