000 AXNT20 KNHC 012240 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 640 PM EDT Tue Sep 1 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 2200 UTC. ...SPECIAL FEATURES... Tropical Storm Nana is centered near 16.8N 79.3W at 01/2100 UTC or 370 nm E of Limon Honduras moving W at 16 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Scattered moderate isolated strong convection is noted within 150 nm N semicircle. Nana will be moving near but north of the coast of Honduras on Wed and likely be approaching the coast of Belize on Thu. Strengthening is forecast during the next 48 hours, and Nana could become a hurricane just prior to landfall on Thu. 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 Storm Omar is centered near 35.3N 71.5W at 01/2100 UTC or 200 nm E of Cape Hatteras North Carolina moving ENE at 13 kt. Estimated minimum central pressure is 1007 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Scattered moderate convection is noted within 150 nm SE quadrant. Omar will continue to move away from North Carolina. Little change in strength is expected overnight, following by weakening beginning on Wed night. Omar is expected to degenerate into a remnant area of low pressure by late Thu. 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... A tropical wave is expected to emerge off the coast of Africa in about a day and merge with a disturbance centered about 200 miles southeast of the Cabo Verde Islands in a couple of days. Gradual development of this system is then possible, and this system could become a tropical depression by this weekend while it moves slowly westward over the eastern tropical Atlantic Ocean. This system has a medium chance of tropical cyclone formation during the next five days. Please see the North Atlantic Tropical Weather Outlook for the latest updates. An eastern Atlantic tropical wave has an axis along 29W from 15N southward, moving W at 10 kt. Scattered moderate to isolated strong convection is noted from 08N to 13N between 23W and 29W. A central Atlantic tropical wave has an axis along 42W from 16N southward, moving W at 10-15 kt. Scattered moderate convection is from 10N to 14N between 36W and 42W. A central Atlantic tropical wave has an axis along 53W from 18N southward, moving W at 10 kt. No significant convection is noted with the wave at this time. An eastern Caribbean tropical wave has an axis along 66W from 20N southward, moving W at 10-15 kt. No significant convection is noted with the wave at this time. A western Caribbean tropical wave has an axis along 79W from 15N southward across Panama and into the far eastern Pacific, moving W at 15 kt. Associated convection with this wave is located in the Pacific off the coast of eastern Panama. ...MONSOON TROUGH/ITCZ... The monsoon trough extends off the coast of Mauritania near 17N16W to 11N26W to 13N34W to 10N43W to 13N47W. Besides the convection described above, scattered moderate convection is occurring from 07N to 15N between 20W to 33W. GULF OF MEXICO... A surface high pressure ridge extends westward across the northern Gulf of Mexico, with 1018 mb high pressure analyzed near 27N85W. Moderate to fresh SE to S winds prevail west of the ridge across the waters W of 91W. Buoy 42019 off the coast of southern Texas recently reported 8 ft seas, while elsewhere seas are generally 5-7 ft across this area. Over the eastern Gulf, light to gentle winds are occurring with seas 3 ft or less. Radar imagery depicts isolated showers and thunderstorms off the coast of southwest Florida this evening. Elsewhere, no significant convection is noted across the offshore waters. High pressure over the eastern Gulf will support moderate to fresh southerly winds over the western Gulf, and light to gentle breezes over the eastern Gulf through mid week. The high pressure will lift north of the area later in the week ahead of a trough entering the eastern Gulf. CARIBBEAN SEA... Please see the Special Features section above for information about Tropical Storm Nana. A broad area of moderate to fresh winds was shown in earlier scatterometer data in the northern semicircle of T.S. Nana, including through the Windward Passage. Outside of Nana, gentle winds prevail across much of the eastern, southern, and NW Caribbean waters. Highest seas are located in the northern semicircle of Nana, likely in the 8-12 ft range. Elsewhere, seas are less than 8 ft across the remaining waters. Scattered moderate to strong convection is noted in GOES-16 satellite imagery and lightning data over eastern Cuba and Hispaniola, approaching the Windward Passage this evening. Nana will move to 17.1N 81.5W Wed morning, 17.3N 84.7W Wed afternoon, then strengthen to a hurricane near 17.2N 87.3W Thu morning. Nana will move inland and weaken to a tropical storm near 16.9N 89.4W Thu afternoon, then weaken further to a remnant low near 16.5N 91.7W Fri morning. Nana will dissipate Fri afternoon. ATLANTIC OCEAN... Please see the Special Features section above for information about Tropical Storm Omar. A subtropical ridge axis extends westward from 1024 mb high pressure near 33N49W across the central and western Atlantic toward the Florida peninsula. Moderate to occasionally fresh NE to E winds are occurring south of the ridge across the central and western Atlantic waters, with seas ranging from 5-7 ft. A surface trough analyzed from 31N63W to 24N68W bisects the ridge axis over the western Atlantic, with scattered moderate convection noted near and east of the Turks and Caicos Islands. Farther east, fresh to locally strong winds are occurring south of the monsoon trough, generally E of 35W. A ridge extending from near Bermuda to the northern Bahamas will lift north tonight, while a westward moving trough approaching the Turks and Caicos Islands this evening passes through the southern Bahamas. The trough will move west of the area Thu, supporting fresh to locally strong winds off Hispaniola and the approaches to the Windward Passage Wed night into Thu morning. The ridge will remain along 29N Thu and Fri, supporting moderate to fresh trades south of 27N. $$ B Reinhart