000 AXNT20 KNHC 241751 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 151 PM EDT Mon Aug 24 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 1715 UTC. ...SPECIAL FEATURES... Tropical Storm Laura is centered near 21.2N 80.6W or about 56 nm east-southeast of Cayo Largo, Cuba and 126 nm east of the Isle of Youth moving WNW, or 285 degrees, 17 kt. The estimated minimum central pressure is 1002 mb. The maximum sustained wind speeds are 50 kt with gusts to 60 kt. Laura has acquired a well pronounced banding feature to the south of the center. Scattered moderate to strong convection is from 16N-23N between 76W-84W. Some decrease in forward speed is expected over the next day or so. A turn toward the northwest is forecast by Wednesday, and a northwestward to north-northwestward motion should continued through Wednesday night. On the forecast track, the center of Laura will move over the Caribbean Sea just offshore of the southern coast of Cuba this afternoon, cross western Cuba this evening, and move into the southeastern Gulf of Mexico overnight. Laura is then forecast to move over the central and northwestern Gulf of Mexico Tuesday night and Wednesday, and approach the northwestern coast of the Gulf of Mexico Wednesday night. 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 Storm Marco is centered near 28.5N 88.5W or about 48 nm southeast of the mouth of the Mississippi River moving north- northwest or 330 degrees at 7 kt. The estimated minimum pressure is 1006 mb, The maximum sustained wind speeds are 45 kt with gusts to 55 kt. Satellite imagery shows that Marco is undergoing southwesterly vertical shear and as a result is on a weakening trend as its center is entirely exposed within 50 nm to the southwest of a large area of scattered moderate to strong convection from 28N-32N between 84W-88W to include the Florida panhandle. A turn to the west-northwest is expected to occur by Tuesday, and this motion should continue until the system dissipates in a couple of days. Marco is expected to produce total rainfall accumulations of 3 to 6 inches with isolated maximum amounts of 10 inches across portions of the northeast and north-central Gulf coast through Tuesday. This rainfall may result in areas of flash, urban and small stream flooding along the same area. 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 has its axis along 20W from 02N to 20N, moving westward at 10 to 15 kt. Scattered moderate convection is from 04N-10N between 13W-28W. Scattered showers are elsewhere within 90 nm of the wave axis. A Central Atlantic tropical wave has its axis along 41W from 02N to 18N. It is moving westward at 10-15 kt. This wave is moving through a stable and dry surrounding environment. Only isolated weak showers are noted within 90 nm of wave axis. A trough extends from near 25N55W to 11N60W. Scattered showers are within 180 nm west of the trough. A central Caribbean tropical wave has its axis along 81W south of 15N, moving westward at 10-15 kt. Scattered moderate convection is S of 11N. ...MONSOON TROUGH/ITCZ... The monsoon trough axis passes through the northernmost coastal sections of Mauritania southwestward to 15N25W to 10N29N and west to 09N39W. The ITCZ axis extends from 09N43W to 08N52W to 11N58W. Besides the convection mentioned in the tropical wave section, scattered showers are within 120 nm of the monsoon trough and ITCZ. GULF OF MEXICO... Please see the Special Feature section above for further details on Tropical Storm Marco and on Tropical Storm Laura soon to enter the basin. Other than Tropical Storm Marco, generally weak high pressure is present over the area. ASCAT data shows gentle to moderate winds over most of the Gulf, with the exception of the areas surrounding Marco. Elsewhere, isolated moderate convection is over the Straits of Florida E of 83W. Over the Bay of Campeche, scattered moderate convection is from 18N-23N between 94W-97W. Tropical Storm Marco is near 28.5N 88.5W 1006 mb at 11 AM EDT moving NNW at 7 kt. Maximum sustained winds 45 kt gusts 55 kt. Marco will move inland to 29.2N 89.3W this evening, weaken to a remnant low near 30.0N 91.3W Tue morning, 30.5N 93.6W Tue evening, 30.9N 95.9W Wed morning, and dissipate Wed evening. Tropical Storm Laura is near 21.2N 80.6W 1002 mb at 11 AM EDT moving WNW at 17 kt. Maximum sustained winds 50 kt gusts 60 kt. Laura will move to 22.2N 82.9W this evening, 23.6N 86.0W Tue morning, strengthen to a hurricane near 25.2N 88.8W Tue evening, 26.8N 91.1W Wed morning, 28.7N 92.8W Wed evening, and inland to 31.2N 93.3W Thu morning. Laura will weaken to a tropical depression while moving inland near 36.0N 90.9W by early Fri. CARIBBEAN SEA... Please see the Special Feature section above for further details on Tropical Storm Laura. Outside convection associated with Tropical Storm Laura and the tropical wave along 77W, an area of scattered isolated thunderstorms is over the eastern Caribbean south of 15N and east of 67W to the Windward Islands. Similar activity is over the far northeast part of the Caribbean to the northern Leeward Islands. Increasing activity, in the form of scattered showers and thunderstorms moving to the southwest are seen over the British and U.S. Virgin Islands to over eastern Puerto Rico. This activity is being enhanced by an upper-level low that is over the Atlantic near 22N62W. It is moving toward the west. Tropical Storm Laura near 21.2N 80.6W 1002 mb at 11 AM EDT moving WNW at 17 kt. Maximum sustained winds 50 kt gusts 60 kt. Laura will move to 22.2N 82.9W this evening, 23.6N 86.0W Tue morning, strengthen to a hurricane near 25.2N 88.8W Tue evening, 26.8N 91.1W Wed morning, 28.7N 92.8W Wed evening, and inland to 31.2N 93.3W Thu morning. Laura will weaken to a tropical depression while moving inland near 36.0N 90.9W by early Fri. ATLANTIC OCEAN... A 1021 mb high is centered over the W Atlantic near 32N70W. A 1024 mb high is centered over the E Atlantic near 33N34W. An upper-level low is near 22N62W moving westward. An upper trough extends from the low south-southeastward to 15N61W and to near 12N61W. Satellite imagery shows increasing scattered showers and thunderstorms from eastern Puerto to the U.S. and British Virgin northward to 23N and between 60W-67W. The pressure gradient between the E Atlantic high and the lower pressures over W Africa supports near gale force winds over the Canary Islands. $$ Formosa