000 AXNT20 KNHC 281745 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 200 PM EDT Tue Jul 28 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 1200 UTC surface analysis and satellite imagery through 1650 UTC. ...SPECIAL FEATURES... The large 1007 mb low east of the Lesser Antilles is now Potential Tropical Cyclone Nine. The low is centered near 13.8N53.7W at 28/1500 UTC, or about 510 nm east of the Leeward Islands, moving west at 20 kt. Maximum sustained wind speed is 35 kt with gusts to 45 kt. A recent ASCAT pass shows a large area of 25-35 kt winds extending out 360 nm north and northeast of the low center. scattered moderate to strong convection is seen from 10N-16.5N between 48W-62W, including over Trinidad and the southern Windward Islands. The disturbance has a high chance of becoming a tropical storm before it reaches the Leeward Islands early Wednesday. Heavy rainfall could produce life- threatening flash floods and mudslides over the Leeward Islands, Virgin Islands and Puerto Rico tonight through early Thu. Expect tropical storm force winds, hazardous seas and heavy squalls over the NE Caribbean Wed and Wed night. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT4.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMAT4.shtml for more details. ...TROPICAL WAVES... An eastern Atlantic tropical wave with axis through the Cabo Verde Islands along 25W from 05N-21N is moving W at 15 kt. Scattered moderate convection is noted from 08N-12N where the wave meets the monsoon trough. An eastern Caribbean tropical wave with axis along 67/68W from 05N-21N is moving W at 10-15 kt. Isolated moderate convection is along the wave axis. A tropical wave extends across the western Caribbean along 82/83W, south of 18N, moving W at 15 kt. Scattered moderate convection prevails in the vicinity of the wave from 10N-15N between 80W-85W, including over eastern Nicaragua and northern Costa Rica. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of northern Senegal near 16N17W to 09N28W to 09N35W to 12N44W. Numerous moderate scattered strong convection is from 07N-11N between 31W-37W. GULF OF MEXICO... An upper-level low is centered near the coast of southern Texas. As a result, upper-level diffluence is enhancing numerous moderate scattered strong convection over the west-central Gulf from 23N-27.5N between 93W-97.5W. Scattered moderate convection is elsewhere from 18N-28N between 92.5W-98W. The sea breeze appears to be enhancing scattered moderate tstorms firing up along the coast of the Florida Panhandle and Florida Big Bend. Similar sea breeze convection is along the coast and a few miles inland between Corpus Christi Texas and Lake Charles Louisiana. Surface ridging prevails over the eastern and central Gulf. Surface ridging will dominate the Gulf waters through Fri supporting mainly gentle to moderate return flow. A surface trough will develop over the Yucatan Peninsula each evening, shift westward into the SW Gulf waters each night, and dissipate over the SW Gulf each morning. Fresh to locally strong easterly winds associated with this trough will affect the Yucatan Peninsula and adjacent waters and the SW basin through this period. CARIBBEAN SEA... Potential Tropical Cyclone Nine is forecast to bring tropical storm conditions to the northeastern Caribbean Wed and Wed night. See the Special Features section above for details. Two tropical waves are currently bringing showers and tstorms to portions of the basin. See the Tropical Waves section for details. The latest ASCAT pass shows fresh trades occurring over much of the basin. Fresh to strong trade winds will prevail over Colombia adjacent waters and in the Gulf of Honduras through Wed night. Strong winds and building seas associated with Potential Tropical Cyclone Nine will begin to affect the Leeward and Virgin Islands tonight. These conditions will shift to Puerto Rico and the Mona Passage early on Wed and continue through Thu evening. Tropical storm force winds and hazardous seas are expected over much of this region. Fresh to strong NE winds are expected Wed night through Thu night across the Windward Passage and Cuba adjacent waters. ATLANTIC OCEAN... Potential Tropical Cyclone Nine is forecast to bring tropical storm conditions today to the Tropical N Atlantic waters east of the Caribbean. The system is forecast to bring tropical storm conditions to the waters near the Greater Antilles and Bahamas Wed night through Fri. See the Special Features section above for more details on this system. Upper-level divergence is enhancing scattered showers and isolated storms well east of northern Florida and north of the NW Bahamas from 28N-32N between 73W-80W. A surface ridge extending from the Azores to a 1025 mb high near 30N41W to southern Florida is keeping benign weather across the remainder of the basin, east of 70W and north of 24N. Fresh winds are expected south of 25N and west of 65W through tonight, increasing to strong north of Hispaniola. Strong winds and building seas associated with Potential Tropical Cyclone Nine will begin to affect the Leeward and adjacent Atlantic waters tonight. These conditions will shift westward across the Virgin Islands, Puerto Rico and the Mona Passage early on Wed and continue through Thu evening. Heavy showers and tstms are expected to affect the Bahamas, Turk and Caicos, and the Greater Antilles adjacent waters during that period. $$ Hagen