000 AXNT20 KNHC 011000 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 600 AM 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 0600 UTC surface analysis and satellite imagery through 1000 UTC. ...SPECIAL FEATURES... Tropical Depression Fifteen is centered near 34.1N 74.4W at 01/0900 UTC, or 86 nm SE of Cape Hatteras North Carolina, moving NE at 11 kt. Estimated minimum central pressure is 1008 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Scattered moderate convection is within 180 nm in the SE semicircle. 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. Caribbean gale warning: A seemingly well-organized cluster of showers and thunderstorms associated with a tropical wave is moving quickly westward across the central Caribbean Sea, but satellite- derived wind data from a few hours ago again showed that the system has not developed a closed surface wind circulation. A recent ship observation south of Jamaica indicated winds were reaching minimal gale force in the area of thunderstorms associated with this disturbance, and a gale warning has been issued accordingly. Environmental conditions are expected to become a little more conducive for development, and there is a high chance that a tropical depression will form during the next couple of days before the system reaches Central America Wednesday night. Locally heavy rains and gusty winds are possible on Jamaica today, and interests there, as well as in northern Nicaragua, Honduras, Belize, Guatemala, and the Yucatan Peninsula, should monitor the progress of this disturbance. ...TROPICAL WAVES... An eastern Atlantic tropical wave has an axis along 28W from 18N southward, moving W at 10-15 kt. Scattered moderate to isolated strong convection is noted from 08N to 12N between 26W and 29W. A central Atlantic tropical wave has an axis along 39W from 16N southward, moving W at 10-15 kt. Scattered moderate convection is from 07N to 09N between 36W and 40W. A central Atlantic tropical wave has an axis along 52W from 18N southward, moving W at 10 kt. Scattered moderate convection from 10N to 12N between 50W and 53W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends off the coast of Senegal near 14N17W to 11N23W to 12N33W to 10N45W to 11N50W to 09N55W. Aside from the convection described in the tropical wave section, scattered moderate to isolated strong convection is from 09N to 12N between 20W and 24W, and from 10N to 12N between 40W and 45W. GULF OF MEXICO... A surface ridge extends from southwest Florida to south Texas. This pattern is maintaining light to gentle winds and 2 to 4 ft seas over the eastern Gulf, and mostly moderate to fresh winds and 4 to 6 ft seas over the western Gulf. There are occasionally fresh to strong southerly winds along the Veracruz coast, between the ridge and higher terrain inland. No significant shower or thunderstorm activity is observed this morning across the Gulf. The ridge will lift northward starting mid week ahead of a surface trough entering the eastern Gulf by Thu. CARIBBEAN SEA... Please see the Special Features section above for information regarding the potential for tropical cyclone development over the central Caribbean Sea. A surface trough is moving across the Virgin Islands, Puerto Rica and Mona Passage this morning, as well as the far northeast Caribbean. A few showers are noted in that area this morning. Fresh NE winds were observed ahead of the trough in the Windward Passage on an earlier scatterometer satellite pass. These winds will diminish through the morning as the trough approaches. Moderate winds and 3 to 5 ft seas are noted elsewhere across the Caribbean. Fresh easterly winds and 4 to 6 ft seas will persist over the north central Caribbean through mid week, expanding into the south central Caribbean and increasing by Sat as high pressure builds north of the area. ATLANTIC OCEAN... Please see the Special Features section above for more information about Tropical Depression Fifteen. A subtropical ridge axis extends from 1025 mb high pressure near 34N44W westward to the eastern Gulf of Mexico. Scattered showers and thunderstorms are noted north of Puerto Rico and Hispaniola near a surface trough that extends from 22N64W to 17N64W. Elsewhere, moderate to locally fresh trades persist over the central Atlantic, with 5-7 ft seas based on earlier altimeter passes. Over the western Atlantic, the ridge will lift north today as the trough moves northwest into the southern Bahamas by late today. The trough will move west of the area Thu, supporting fresh to 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. Farther east, generally moderate trade winds and 5 to 7 ft seas are observed across the eastern Atlantic. $$ Christensen