000 AXNT20 KNHC 100005 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Tue Aug 10 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 2345 UTC. ...SPECIAL FEATURES... Newly classified Potential Tropical Cyclone Six is centered near 14.7N 60.1W at 10/0300 UTC or 78 nm ESE of Dominica and about 115 nm SE of Guadeloupe moving WNW at 13 kt. Estimated minimum central pressure is 1010 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Satellite imagery shows that deep convection of the scattered moderate to strong type intensity has during the afternoon within 120 nm of the center in the northern semicircle and within 90 nm of the center in the SE quadrant. Its overall cloud pattern has become more symmetrical during the past few hours as outer rain bands are just east of the Leeward Islands. These bands consist of scattered moderate to isolated strong convection from 16N to 18N between 58W-61W. Potential Cyclone Six is forecast to maintain its current motion during the next few days. On the current forecast track, the Potential Cyclone Six is expected to move through a portion of the southern Leeward Islands later tonight, pass near or over the U.S. Virgin Islands and Puerto Rico late Tue and Tue night, and near or over Hispaniola on Wed. Potential rainfall amounts of 2-4 inches, with isolated amounts of 6 inches are expected over the Leeward Islands, Virgin Islands, and Puerto Rico. This rainfall could lead to flash, urban, and small stream flooding and potential mudslides across the U.S. Virgin Islands and Puerto Rico. 3-6 inches of rainfall are expected over the Dominican Republic and 1-3 inches over the northern Windward Islands. Tropical storm conditions are possible within the watch area in the Lesser Antilles later tonight, and are also possible within the watch area in the U.S. Virgin Islands and Puerto Rico beginning Tue afternoon. Tropical storm conditions are possible within the watch area in the Dominican Republic beginning early Wed. Wave heights with Potential Cyclone-Six are forecast to build to near 12 ft on Tue. It has a high chance of becoming a tropical cyclone formation during the next 48 hours. For more details on Potential Tropical Cyclone Six please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website- https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest Potential Tropical Cyclone Six NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov. ...TROPICAL WAVES... An eastern Atlantic tropical wave has its axis along 20W from 05N to 22N, moving westward at 10 kt. Scattered moderate to isolated strong convection is within 60 nm west of the wave from 10N to 14N. Another eastern Atlantic tropical wave has its axis along 37W from 03N to 22N, moving westward at 10-15 kt. Only small isolated showers and thunderstorms are noted within 180 nm either side of the wave axis from 03N to 09N. A central Atlantic tropical wave has its axis extending from inland South America near 04N5W north-northeastward to 17N57W and to 25N55W, It is moving westward at 13 kt. Scattered moderate convection is within 120 nm east of the wave from 16N to 19N. A central Caribbean Sea tropical wave has its axis along 73W south of 20N to inland South America. It is moving westward at 10-15 kt. Scattered moderate convection is near the northern part of this wave over northern Haiti and within 180 nm west of the wave from 17N to 20N noted from 11N to 15N between 55W an 60W. ...MONSOON TROUGH/ITCZ... The monsoon trough axis passes through Mauritania near 20N16W to 13N30W to 10N46W, where latest scatterometer data indicates the ITCZ begins and continues to 10N53W. Aside from convection described above in the Special Features and Tropical Waves sections, scattered moderate convection is seen from 05N to 10N between 47W-52W and from 04N to 07N between 41W-47W. ...GULF OF MEXICO... High pressure of 1021 mb high is centered over the NE Gulf near 29N87W. Ridging from this and the subtropical high dominates the Gulf waters allowing for fairly tranquil conditions. Scattered moderate convection is noted from 24N to 25N between 84W-90W. Light anticyclonic winds are observed in the NE Gulf near the high center. Gentle to moderate east to southeast winds are found elsewhere in the Gulf. Seas are 3-5 ft in the NW Gulf, 2-4 ft in the SW and central Gulf, and 1-3 ft in the E Gulf. For the forecast, moderate to fresh east winds will pulse off the northwest Yucatan Peninsula into the Bay of Campeche each night through Wed night in association with a diurnal trough. Elsewhere, a weak surface ridge along 27N will dominate the Gulf waters today, and drift northward to along 30N Tue through Thu. Newly classified Potential Tropical Cyclone Six is located near 14.2N 59.2W 1010 mb at 2100 UTC moving WNW 13 kt. Maximum sustained winds 30 kt gusts to 40 kt. This system is expected to move across the central Lesser Antilles tonight and intensify to a tropical storm, then continue west-northwest across the northeastern Caribbean Tue, across northeastern Hispaniola early Wed, and then continue offshore and parallel to the north coast of Cuba Thu through Fri and across the Straits of Florida and into the southeastern Gulf of Mexico Sat. ...CARIBBEAN SEA... Please see the Special Features section for details on newly classified Potential Tropical Cyclone Six. High pressure is present north of the area. Scattered showers and isolated thunderstorms are over the far SW Caribbean near the eastern segment of the East Pacific monsoon trough. Similar activity is over the northwestern Caribbean. Isolated showers and thunderstorms are over the waters between Haiti and Jamaica and between Jamaica and 80W. Fresh to locally strong trades are over the south-central Caribbean. Moderate to fresh trades are elsewhere over the basin, except over the northwestern Caribbean, where trades are in the gentle to moderate speeds. Seas are 5-7 ft near the Lesser Antilles, 4-6 ft in the central Caribbean, 3-5 ft in the SW Caribbean, and 2-4 ft in the NW Caribbean. For the forecast, fresh to strong trade winds over the central Caribbean tonight will give way to a developing Tropical Cyclone approaching the Lesser Antilles tonight. Potential Tropical Cyclone Six is located near 14.2N 59.2W 1010 mb at 2100 UTC moving W-NW 13 kt. Maximum sustained winds 30 kt gusts to 40 kt. This system is expected to move across the central Lesser Antilles tonight and intensify to a tropical storm, then continue W-NW, reaching near 16.8N 64.5W Tue afternoon, move across the Mona Passage and into northeastern Hispaniola early Wed, and then continue offshore and parallel to the northern coast of Cuba Thu through Fri and across the Straits of Florida and into the southeastern Gulf of Mexico Sat. ...ATLANTIC OCEAN... Please see the Special Features section for information on newly classified Potential Tropical Cyclone Six. Three subtropical highs present. One of 1027 mb centered near 34N44W, the other of 1029 mb centered near 36N35W and the other of 1026 mb centered near 34N56W 1026 mb dominate the weather regime across the tropical Atlantic. Light to gentle east to southeast winds remain over the waters north of 23N and west of 57W, with moderate to locally fresh trades from 15N to 23N, and gentle to moderate trades south of 15N across the basin. Seas are 3-5 ft north of 22N and west of 65W, and generally 4-7 ft elsewhere in the discussion waters outside of the area described in the Special Features section. For the forecast W of 65W, the Atlantic surface ridge associated with the Bermuda-Azores high will persist with axis north of the area for the next several days. Newly classified Potential Tropical Cyclone Six is located near 14.2N 59.2W 1010 mb at 2100 UTC moving W-NW 13 kt. Maximum sustained winds 30 kt gusts to 40 kt. This system is expected to move across the central Lesser Antilles tonight and intensify to a tropical storm, then continue W-NW, move across the Mona Passage and into NE Hispaniola early Wed, and then continue offshore and parallel to the northern coast of Cuba Thu through Fri and across the Straits of Florida and into the SE Gulf of Mexico Sat. $$ Aguirre