000 AXNT20 KNHC 041803 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 205 PM EDT Tue Aug 04 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 1745 UTC. ...SPECIAL FEATURES... As of 04/1500 UTC, the center of Tropical Storm Isaias was located by NOAA Doppler weather radars and surface observations near latitude 39.1 North, longitude 76.1 West, moving quickly NNE at 35 mph. Maximum sustained winds are near 60 kt, 70 mph with higher gust. On the forecast track, the center of Isaias will continue to move near or along the coast of the mid- Atlantic states today, and move across the northeastern United States into southern Canada tonight. Only gradual weakening is anticipated while Isaias moves north-northeastward near the mid- Atlantic coast today. A faster rate of weakening is expected to begin tonight, and the system is forecast to become post- tropical tonight or early on Wed. 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... A far eastern Atlantic tropical wave with its axis along 23W from 03N-18N, moving westward at 10-15 kt. The wave is embedded within deep tropical moisture south of 13N. Scattered moderate isolated strong convection is seen from 02N-13N between 20W-27W south of the African monsoon trough. An eastern Atlantic tropical wave has its axis along 35W from 02N-18N, moving westward at about 10-15 kt. This wave is embedded within deep tropical moisture south of 16N. Scattered showers and thunderstorms are seen south of the monsoon trough in that area of the Atlantic, from 02N to 09N between 31W and 40W. A central Atlantic tropical wave has its axis along 48W, from 16N south, moving westward at 15 kt. Scattered showers and thunderstorms are noted ahead of the wave, from 08N-13N between 46W and 51W. A central Caribbean tropical wave has its axis along 79W from 00N-18N, moving westward at 15-20 kt. Scattered moderate convection is enhanced by the Pacific monsoon trough from the coast of Panama to 11N. Scattered showers and thunderstorms are seen over and north of Jamaica. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends from the coast Africa near 18N16W to 09N3W to 07N46W. The ITCZ extends west of a tropical wave from 08N51W to 07N59W. Aside to the convection associated to the tropical waves, scattered moderate convection is within 300 nm S of the monsoon trough. Also, an area of scattered moderate isolated strong convection is observed along the coast of Africa from Guinea to Senegal. Scattered showers are noted along the ITCZ from 07N-11N between the coast of Brazil to 51W. GULF OF MEXICO... Surface ridging prevails across the basin, anchored by a 1015 mb high entered near 24N90W. Scatterometer data depicted light to gentle anticyclonic winds across the whole area, with seas ranging between 2-4 ft. Scattered showers are noted over the Bay of Campeche and the SE Gulf. In the forecast, the weak high pressure will persist over the N Gulf this week, maintaining gentle flow across much of the region with moderate to fresh winds expected across the eastern Bay of Campeche. CARIBBEAN SEA... Refer to the section above for details on the tropical wave over the central part of the basin. Scattered showers and thunderstorms are noted across the waters from Jamaica west to 84W. To the south, the EPAC monsoon trough extends Along 11N between 75W-83W where active convection prevails. ASCAT data indicated gentle to moderate trades across the basin except south of 15N between 64W-75W, where moderate to fresh easterly winds were noted. Dry conditions remained elsewhere. The Bermuda High north of the area along with the typical eastward extension of the NE Pacific monsoon trough to Colombia will contribute toward fresh to strong E trades over the central Caribbean through Sat night. Elsewhere winds and seas are at or below normal. No tropical cyclone formation is expected in these waters for the next several days. ATLANTIC OCEAN Refer to the sections above for details on Tropical Storm Isaias and the tropical waves moving across the basin. Scattered moderate convection continues over the northwest waters W of 75W, extending from north of the Bahamas to 31N. To the east, a surface trough extends from 23N72W to 29N65W will continue towards the NW across the Atlantic waters then weaken tonight and Wed. A second trough is noted from 20N39W to 29N39W. No significant convection is noted with the trough. Surface ridging extends from the NE Atlantic southwestward and south of a stationary front that extends from a 1016 mb low near 32N48W to 29N57W to 30N64W. Scattered showers and thunderstorms are 160 nm SE of the boundary between 56W to 50W. In the forecast, high seas north of 29N associated with Tropical Storm Isaias will shift northward and exit the waters west of 75W, allowing seas to gradually subside there today through tonight. Weak troughing will linger across the waters north of 25N and west of 50W through Fri, leading to gentle to moderate winds across most of the area waters. The surface trough NE of the southern Bahamas will move NW across the area today then weaken tonight and Wed. Moderate to locally fresh easterly winds are expected across the Great Bahama Bank and N of Hispaniola through the weekend. $$ Torres