000 AXNT20 KNHC 141805 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Sat Aug 14 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 1200 UTC surface analysis and satellite imagery through 1755 UTC. ...SPECIAL FEATURES... The remnants of Fred are in the SE Gulf of Mexico, off the NW coast of Cuba, near 23.3N 83.2W at 1500 UTC, or about 110 nm SW of Key West, Florida. It is moving WNW at 10 kt with an estimated minimum central pressure at 1013 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Wave heights with the remnants of Fred are in the 8-10 ft range. Latest satellite imagery shows scattered moderate to isolated strong convection affecting from 19N to 27N and between 77W to 88W. Fred is expected to turn toward the northwest by tonight, followed by a northward motion by Sunday night. On the forecast track, Fred or its remnants are expected to pass west of the lower Florida Keys this afternoon, move across the eastern Gulf of Mexico tonight through Monday, and move inland over the northern Gulf coast Monday night.Fred is expected to re- develop into a tropical depression on Sunday, with gradual strengthening to a tropical storm expected after the system re- develops. 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 NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Tropical Storm Grace is quickly approaching the Lesser Antilles, located near 16.2N 58.7W at 1800 UTC or about 160 nm east of the Leeward Islands. It is moving W at 20 kt, with an estimated minimum central pressure of 1007 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Wave heights with this system are in the 9-12 ft range. Visible satellite imagery shows a small tropical storm that is producing strong thunderstorms, but there are no signs of banding. Most of the convection is located west of the center, and is already affecting some of the Leeward Islands. Grace is forecast to move toward the west- northwest with a gradual decrease in forward speed during the next several days. On the forecast track, the center of Grace is expected to move over the Leeward Islands tonight, over the Virgin Islands and Puerto Rico on Sunday, over the Dominican Republic on Monday, and then between the southeastern Bahamas and Cuba on Tuesday. Some strengthening is forecast during the next day or so. Grace is likely to weaken while it moves near and across the Greater Antilles Sunday night through Monday night. 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 NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...TROPICAL WAVES... An Atlantic tropical wave has its axis along 20W, south of 20N, and it is moving W at about 15 kt. Scatterometer satellite data show a broad curvature between Africa and the Cabo Verde Islands, which is difficult to distinguish from the nearby monsoon trough. Scattered moderate convection is noted from 06N to 12N and between the coast of Africa to 23W. Another Atlantic tropical wave has its axis along 33W, south of 20N, and it is moving W at around 20 kt. The wave is surrounded by a dry environment, inhibiting the development of showers and thunderstorms. A Caribbean tropical wave has its axis along 68W, south of 24N, and it is moving W at around 10 kt. Recent scatterometer satellite data depict a broad surface trough, especially on the northern portion of the wave. The plume of moisture associated with the wave is interacting with an upper level low south of Bermuda, resulting in a large area of showers and isolated thunderstorms from 21N to 27N and between 57N and 70W. Another area of scattered moderate convection is found in the Caribbean Sea near the wave axis from 13N to 16N. Another Caribbean tropical wave has its axis along 85W, south of 19N, extending from the NW Caribbean to the E Pacific, and it is moving W at around 10 kt. The convection associated with this wave is occurring on the Pacific side. ...MONSOON TROUGH/ITCZ... The monsoon trough extends across the coast of Mauritania near 18N16W to 07N27W and to 06N36W. The ITCZ then continues from 06N37W to 05N44W and to 06N52W. Scattered moderate convection is noted near the monsoon trough between 23W and 31W. Another area of scattered moderate convection is found within 250 nm north of ITCZ between 42W and 50W. ...GULF OF MEXICO... Refer to the Special Features section for information on the remnants of Fred. An upper level low over the E Gulf of Mexico is interacting with the remnants of Fred, causing a large area of showers and isolated thunderstorms from 21N to 26N and between SW Florida and 88W. Isolated showers are also noted in the central-north Gulf from 23N to the coast of Louisiana and between 89W and 93W. The rest of the basin enjoys fairly tranquil weather conditions. Outside of the influence of Fred, gentle to moderate NE winds and seas are 2-4 ft prevail. For the forecast, the remnants of Fred near 23.3N 83.2W 1013 mb at 11 AM EDT moving WNW at 10 kt. Maximum sustained winds 30 kt gusts 40 kt. Fred will move to 24.1N 84.2W this evening, 25.7N 85.5W Sun morning, 27.4N 86.7W Sun evening, 28.7N 87.4W Mon morning, 30.0N 87.7W Mon evening, and inland to 31.5N 87.5W Tue morning. Fred will move inland over 35.0N 86.5W by early Wed. ...CARIBBEAN SEA... Refer to the Special Features section for information on Tropical Storm Grace and the Tropical Waves section for convection in the Caribbean Basin. The E Pacific monsoon trough extends into the SW Caribbean and it is producing an area of moderate scattered convection between the coast of Costa Rica and NW Colombia and within 150 nm north of the coast of Panama. Moderate to occasionally fresh trades and seas of 5-7 ft are noted in the central Caribbean, while gentle to moderate trades and seas of 3-5 ft are found in the E Caribbean. Light to gentle trades and seas of 1 to 3 ft are elsewhere over the basin. For the forecast, Tropical Storm Grace near 16.2N 57.9W 1005 mb at 11 AM EDT moving W at 20 kt. Maximum sustained winds 40 kt gusts 50 kt. Grace will move to 16.8N 60.6W this evening, 17.5N 63.8W Sun morning, inland to 18.1N 66.4W Sun evening, inland to 18.6N 68.6W Mon morning, inland to 19.4N 70.7W Mon evening, and 20.5N 72.8W Tue morning. Grace will change little in intensity as it moves to 22.8N 77.3W by early Wed. ...ATLANTIC OCEAN... Refer to the Special Features section for information on Tropical Storm Grace and the Tropical Waves and Monsoon Trough/ITCZ for details on area of convection. An upper level low over the E Gulf is triggering some shower activity along the E coast of Florida and the NW Bahamas. A couple of troughs extend into our area from low pressure system near and SW of the Azores. These troughs are not producing any deep convection. The rest of the basin enjoys fairly tranquil weather conditions. Moderate to locally fresh easterlies and seas of 5-7 ft prevail S of 27N and W of 60W. Also from 10N to 25N and between 30W and the Lesser Antilles, and S of 27N and the coast of Africa to 30W. South of 10N, gentle to moderate winds and seas at 3-5 ft are present. Light to gentle winds and seas of 3-5 ft are found elsewhere in the basin. For the forecast west of 65W, the remnants of Fred near 23.3N 83.2W 1013 mb at 11 AM EDT moving WNW at 10 kt. Maximum sustained winds 30 kt gusts 40 kt. Fred will move to 24.1N 84.2W this evening, 25.7N 85.5W Sun morning, 27.4N 86.7W Sun evening, 28.7N 87.4W Mon morning, 30.0N 87.7W Mon evening, and inland to 31.5N 87.5W Tue morning. Fred will move inland over 35.0N 86.5W by early Wed. Tropical Storm Grace near 16.2N 57.9W 1005 mb at 11 AM EDT moving W at 20 kt. Maximum sustained winds 40 kt gusts 50 kt. Grace will move to 16.8N 60.6W this evening, 17.5N 63.8W Sun morning, inland to 18.1N 66.4W Sun evening, inland to 18.6N 68.6W Mon morning, inland to 19.4N 70.7W Mon evening, and 20.5N 72.8W Tue morning. Grace will change little in intensity as it moves to 22.8N 77.3W by early Wed. $$ DELGADO