000 AXNT20 KNHC 311729 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 129 PM EDT Fri Jul 31 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 1650 UTC. ...SPECIAL FEATURES... The center of Hurricane Isaias at 31/1500 UTC is near 21.7N 74.5W. The center of Isaias is about 315 nm SSE of Great Abaco Island, Bahamas and about 355 nm SE of Nassau, Bahamas. Isaias is moving NW at 14 kt. The maximum sustained wind speeds are 60 kt with gusts to 85 kt. The estimated central pressure is 992 mb. The 12 ft seas extend 300 nm in the NE quadrant, 180 nm in the SE quadrant, 90 nm in the SW quadrant, and 300 nm in the NW quadrant. Most of the precipitation is confined in the northern semicircle of the storm, with numerous moderate to strong convection from 21N-23N between 74W-75W. Scattered moderate to strong convection is noted from 21N-23N between 71W-76W. Scattered showers are noted 120 nm from the center in the SE quadrant. This convection is impacting the southeastern Bahamas with some of the scattered showers impacting the Turks and Caicos. Seas are up to 26 ft near the center of the storm. Isaias will continue its northwestward motion with some decrease in forward speed expected for the next day or so followed by a turn toward the north-northwest. On the forecast track, the center of Isaias will continue to move near or over the Southeastern Bahamas today. Isaias is forecast to be near the Central Bahamas tonight, and move near or over the Northwestern Bahamas Saturday and near the east coast of the Florida peninsula Saturday afternoon through Sunday. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT4.shtml, and the Forecast/Advisory at https://www.nhc.noaa.gov/text/MIATCMAT4.shtml, for more details. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 25W, from 18N southward, moving W at 10 kt. Scattered moderate convection is noted from 08N-12N between 24W-28W. An Atlantic Ocean tropical wave is along 46W, from 18N southward, moving W at 15-20 kt. Scattered moderate convection is near the northern tip of the wave from 14N-16N between 46W-48W. An Atlantic Ocean tropical wave is along 58W, from 18N southward, moving W at 10 kt. There is no significant convection associated with this wave at this time. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Senegal near 15N17W to 12N30W to 09N50W. A 1008 mb low is analyzed along the monsoon trough near 14.2N 19.7W. Scattered moderate convection is noted within 60 nm NW of the low. This low has a low chance of development in the next 48 hours. Scattered moderate convection is south of the monsoon trough from 05N-13N between 29W-45W. GULF OF MEXICO... Upper level ridging spans across the Gulf with a surface high pressure analyzed at 1018 mb near 27N89W. A surface trough is off the Florida coast along 84W from 28N-24N. Some showers are located near this feature. A surface trough is analyzed in the Bay of Campeche from 22N91W to 19N93W. Scattered showers are noted in the western Bay of Campeche, S of 22N. Light to gentle anticyclonic winds are noted across the basin. Seas range 2 to 5 ft. Hurricane Isaias is centered near 21.7N 74.5W 991 mb at 11 AM EDT moving NW at 14 kt. Maximum sustained winds 65 kt gusts 80 kt. Weak high pressure will persist over the northern Gulf through the weekend as Isaias moves near or over the Central and NW Bahamas tonight into Sat, then passes near or east of the Florida peninsula Sat and Sun. Mainly gentle winds will prevail across the Gulf through early next week. CARIBBEAN SEA... A 1010 mb low is located in the west-central Caribbean near 16N78W with a trough extending along the low from 20N76W to 11N82W. Scattered showers are noted within 200 nm of this feature. Scattered showers are also in the Gulf of Honduras/Belize near the tropical wave extending into the eastern Pacific. Enhanced convection is in the SW Caribbean near the monsoon trough, S of 11N between 77W-80W. Moderate to fresh ESE winds are noted in the NE Caribbean in response to Hurricane Isaias. Otherwise, light to gentle winds are in the western Caribbean. Seas range 3 to 6 ft with up to 9 ft near the Greater Antilles. Hurricane Isaias is centered near 21.7N 74.5W 992 mb at 11 AM EDT moving NW at 14 kt. Maximum sustained winds 65 kt gusts 80 kt. Isaias will move to the Central Bahamas near 23.0N 76.1W this evening, then continue moving northward away from the region this weekend. Fresh winds and high seas will prevail today through the Mona Passage and Windward Passage. Fresh to strong flow will persist south of Hispaniola through Fri night. ATLANTIC OCEAN... See the Special Features section for more information on Hurricane Isaias. A trough is analyzed in the central Atlantic from 31N53W to 24N56W with showers within the vicinity of it. A trough also extends off the western African coast from 24N18W to 16N20W with no significant convection associated with it. Otherwise, high pressure dominates the basin. Light to moderate winds cover the Atlantic outside of the vicinity of Isaias. Seas range 4 to 8 ft. Hurricane Isaias is centered near 21.7N 74.5W 992 mb at 11 AM EDT moving NW at 14 kt. Maximum sustained winds 65 kt gusts 80 kt. Isaias will move toward the Central Bahamas near 23.0N 76.1W this evening, near the NW Bahamas 24.8N 78.0W Sat morning, then move near the east coast of the Florida Peninsula to 26.3N 79.2W Sat evening, 27.7N 79.8W Sun morning, 29.2N 80.0W Sun evening, and 31.6N 79.5W Mon morning. Very large seas in SE swell are expected over a large portion of the SW North Atlantic waters near and offshore of the Bahamas tonight into Sat. $$ AReinhart