000 AXNT20 KNHC 172328 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Fri Jun 18 2021 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 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 2315 UTC. ...SPECIAL FEATURES... Potential Tropical Cyclone Three is centered near 22.9N 92.4W at 17/2100 UTC or 410 nm S of Morgan City Louisiana moving N at 8 kt. Estimated minimum central pressure is 1008 mb. Maximum sustained wind speed is 25 kt with gusts to 35 kt. At this time, scattered to numerous moderate convection prevails from 20N-29N and east of 90W. On the forecast track, the system will approach the north-central Gulf Coast late Friday or early Saturday. A northeastward motion across the southeastern United States is likely after landfall. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT3.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMAT3.shtml for more details. ...TROPICAL WAVES... An Atlantic tropical wave axis is analyzed along 25W from the Cabo Verde islands near 18N southward, and is moving west at 10 to 15 kt. Scattered moderate convection is noted from 01N to 09N between 20W and 34W. Another Atlantic tropical wave axis is along 45W from 19N southward, moving west at 15 to 20 kt. Scattered showers are noted from 06N to 13N between 43W and 50W. A Caribbean tropical wave axis is analyzed near 64W from 19N southward into Venezuela, and is moving W at around 15 to 20 kt. Scattered moderate convection is present from 07N to 18N between 60W and 70W. Stronger thunderstorms might produce fresh gusty winds across the Lesser Antilles. Another Caribbean tropical wave axis is analyzed along 83W from 18N southward over western Panama, and is moving west at 5 to 10 kt. Scattered moderate convection is evident along the coasts of Colombia, Panama, and Costa Rica mainly in association with the monsoon trough currently extending along 09N. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coast of Africa near 11N16W to 05N27W. Segments of the ITCZ then continue westward from 05N27W to 06N38W and from 05N47W to 06N53W. Aside from the convection described with the tropical waves in the section above, no significant activity is noted at this time. GULF OF MEXICO... Refer to the Special Features section above for details on Potential Tropical Cyclone Three. A surface trough extends northeastward from the low to 26N88W. Fresh to strong winds were detected by the latest scatterometer passes. Aided by upper-level divergent flow, scattered to numerous moderate convection is occurring from the Yucatan Channel north to 29N between the Florida Gulf coast and 90W. This convection is also impacting portions of the Yucatan Channel and NW Caribbean. A stationary front stretches eastward from 29N95W across the northeastern Gulf to northern Florida at 30N86W. No convection is noted with the front at this time. Gentle to moderate E winds are noted in the northern Gulf north of 26N, moderate to locally fresh E-SE winds are noted south of 26N and east of 94W, with moderate to fresh NE-N winds west of 94W. Finally, in the Bay of Campeche, winds shift cyclonically to S around the broad low pressure. Seas are mainly in the 3-5 ft range, except 4-6 ft in the south central Gulf, southeast Gulf, and Straits of Florida. For the forecast, Potential Tropical Cyclone Three will move to 24.5N 92.5W Fri morning, 26.5N 92.5W Fri afternoon, 29.0N 92.0W Sat morning, inland to 31.5N 89.5W Sat afternoon, inland to 34.0N 87.0W Sun morning, and inland to 35.0N 84.0W Sun afternoon. Three will dissipate Mon afternoon. Heavy rainfall will continue to affect most of the basin through Fri night, and the N and NE basin offshores the remainder weekend. High pressure is forecast to build in across the basin in the wake of Three Sat night into early next week. CARIBBEAN SEA... Two tropical waves are moving across the basin. Refer to the Tropical Waves section above for details. The eastern Pacific monsoon trough extends across Panama to NW Colombia near 10N76W. In the NW Caribbean, scattered moderate convection is noted north of 19N and west of 83W, including inland over the Yucatan Channel and Peninsula. Fresh to strong tradewinds were detected by the latest scatterometer pass in the south central Caribbean. The strongest winds extend from the coast of Colombia north to 13N between 71W and 77W. Mainly moderate to fresh trades prevail elsewhere in the basin, except gentle to moderate in the SW Caribbean south of 11N. Seas of 4-8 ft throughout the basin, except 6-9 ft in the area of strong winds off in the south central Caribbean. For the forecast, a ridge of high pressure north of the basin combined with lower pressure over Venezuela and Colombia will continue supporting pulses of fresh to strong trades over the S central Caribbean and Gulf of Honduras during the weekend and into early next week. Fresh to strong trades will expand in areal coverage and reach Hispaniola adjacent waters over the weekend. Elsewhere, moderate to fresh trades will prevail, except light to gentle variable winds over Panama and Costa Rica adjacent waters. ATLANTIC OCEAN... A pair of tropical waves are moving across the basin. Refer to the Tropical Waves section above for details. Diffluent flow aloft continues to support scattered moderate convection over the Florida Peninsula and western Atlantic mainly north of 27N and west of 66W. To the east, a surface ridge dominates the entire Atlantic forecast area anchored by the Bermuda-Azores High located north of the area. Fresh to locally strong SW winds are occurring in the W Atlantic north of 30N between 68W and 71W. Moderate to fresh trades dominate south of 22N west of 50W. Gentle to moderate trades prevail elsewhere, except from 18N to 24N between the west coast of Africa and 24W where fresh N-NE winds persist due to a locally tight pressure gradient. Seas are 7 to 10 ft in this area of fresh winds. In the Bahamas, seas are 2-4 ft. Outside of these areas, seas of 5 to 8 ft prevail across the waters south of 22N, with mainly 4 to 7 ft seas north of 22N. For the forecast west of 65W, the ridge of high pressure across the area will retreat eastward this evening enabling a trough to move through the northern forecast waters through Fri. High pressure will then return to the area over the weekend into early next week. Fresh to strong winds are expected to pulse at night over Hispaniola adjacent waters during the forecast period and over Puerto Rico adjacent waters tonight. $$ ERA