000 AXNT20 KNHC 141042 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Wed Aug 14 2024 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... Tropical Storm Ernesto: At 500 AM AST (0900 UTC), the center of Tropical Storm Ernesto was located near latitude 19.5 North, longitude 66.6 West, or about 85 nm N-NW of San Juan, Puerto Rico. Ernesto is moving toward the northwest at 14 kt. Maximum sustained winds are 60 kt with gusts to 75 kt, and the minimum central pressure is 996 mb. Peak seas are estimated at 25 ft across the NE quadrant. A turn toward the north-northwest then north with a gradual decrease in forward speed is expected today through Thursday. On the current forecast track, Ernesto is expected to become a hurricane this afternoon, about 190 nm N-NW of San Juan. Puerto Rico, then will continue to gradually strengthen as it moves northward over the western Atlantic through Fri then reach near Bermuda Sat morning. Scattered to numerous rainbands are presently spread across the Virgin Islands, the southeast half of Puerto Rico and across the local coastal waters. These rainbands are producing strong to torrential rainfall. Total rain accumulations of 4 to 6 inches are expected over the U.S and British Virgin Islands, while totals of 6 to 8 inches, with maximum amounts of 10 inches, are expected across southeastern Puerto Rico, with totals of 2 to 4 inches across northwestern Puerto Rico. Heavy rainfall may result in locally considerable flash flooding and mudslides over the Virgin Islands and into portions of Puerto Rico tonight through Wednesday. Large swell from Ernesto will spread northward and into the Turks and Caicos Islands today, across the Bahamas tonight through Thu, and into Florida and the Southeastern U.S. coastlines early Fri through Fri night. This swell will produce large and dangerous surf which will generate life threatening rip currents. 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 Ernesto NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Agadir Gale Warning: The pressure gradient between a 1026 mb Azores high and the low pressures over the west Saharan will support gale-force winds in the METEO-FRANCE forecast area of Agadir from 14/12 UTC to 15/00 UTC. For more information please visit: https://wwmiws.wmo.int/index.php/metareas/display/2. ...TROPICAL WAVES... The axis of an eastern Atlantic tropical wave is along 32W-33W from 05N to 19N, moving west at 5 to 10 kt. No significant convection accompanies this wave. A central Atlantic tropical wave is along 47W from 06N to 16N, moving west at 15 to 20 kt. Scattered moderate to strong convection is depicted from 08.5N to 13N between 45W to 53W. Recent ASCAT pass revealed fresh to localized strong cyclonic winds with this wave. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic off the coast of Africa near 21N17W and extends 15N23W to 11N54W. Scattered to numerous moderate to strong convention is noted from 04.5N to 11N between 22W and the coast of Africa. ...GULF OF MEXICO... Widely scattered moderate convection is noted across the Bay of Campeche south of 22.5N and west of 90W in association with the nocturnal surface trough moving off of the Yucatan Peninsula. Other scattered moderate convection extends from the Yucatan Channel E-NE across the Straits of Florida to the middle Florida Keys. Moderate E winds are over the eastern Bay of Campeche with seas 3 to 4 ft. Otherwise, a weak pressure gradient is supporting light to gentle anticyclonic winds over much of the basin with seas 2 to 3 ft in the SW Gulf, and seas 1 to 3 ft elsewhere. For the forecast, a weak surface ridge will maintain gentle to moderate winds and slight to moderate seas across most of the basin into this weekend. Otherwise, moderate to locally fresh winds are expected along the Yucatan Peninsula each evening through the weekend. ...CARIBBEAN SEA... Please see the Special Features section above for more information on Tropical Storm Ernesto. Associated strong convection extends from 15N across the NE Caribbean and into the local Atlantic, between 62W and 69W. Fresh to strong southerly winds extends from the SE Caribbean east of 68W, northward across the Leeward Islands, Anegada Passage, then become tropical storm force across the Virgin Islands and NE Puerto Rico. Seas are 4 to 6 ft south of 15N there, and 7 to 12 ft north of 15N, higher in the Anegada Passage. A surface trough is analyzed over southern Cuba and is producing isolated moderate convection across the NW part of the basin. Fresh NE winds are noted through the Windward Passage with seas 5 to 7 ft. Otherwise and away from Tropical Storm Ernesto, gentle to moderate winds are noted across much of the basin with seas of 3-5 ft. For the forecast, Tropical Storm Ernesto will move NW and strengthen to a hurricane near 21.1N 67.8W this afternoon, reach near 23.6N 68.9W Wed night, then turn northward and continue to gradually strengthen as it moves across the western Atlantic, reaching near Bermuda Sat morning. In its wake, high pressure will gradually build westward along 21N late Fri into the weekend, bringing a return to a more typical trade wind flow across the basin. ...ATLANTIC OCEAN... Please see Special Features section above for more information about Tropical Storm Ernesto. A broad wind surge has accompanied Ernesto for the past few days, with fresh to strong winds north of the storm extending to 24N. This has produced a large wave field moving in synch with Ernesto, with seas of 8 to 12 ft, and higher near Ernesto, in E swell extending from 17N to 24N between 59W and 70W. High pressure prevails across the tropical and subtropical waters N of 20N, anchored by a 1025 mb high centered near 36N33W. A ridge extends from the high center W-SW along 29N/30N to Florida, favoring light to gentle winds near the ridge axis. Gentle to moderate E and NE winds prevail over much of the waters elsewhere N of 20N with seas 4 to 6 ft, except for fresh to locally strong NE winds and seas of 7 to 9 ft near the Canary Islands. S of 20N, gentle to moderate winds and seas of 4 to 7 ft prevail. A weak front from just N of Bermuda to coastal Georgia is drifting southward, and has produced scattered moderate convection from 30N to the front and west of 65W. For the forecast west of 55W, the ridge from the central Atlantic W-SW to central Florida will shift E and weaken through Thu. Tropical Storm Ernesto will move NW and strengthen to a hurricane near 21.1N 67.8W this afternoon, reach near 23.6N 68.9W Wed night, then turn northward and continue to gradually strengthen, reaching near 25.7N 68.8W Thu afternoon, near 29.5N 66.2W Fri afternoon, then reach near Bermuda Sat morning. In its wake, high pressure will gradually build westward along 21N late Fri into the weekend. A weak frontal boundary will drop southward across the northwestern part of the area beginning late today, and stall to the NW of Ernesto by Fri, producing moderate to fresh NE winds behind it. Large swell from Ernesto will spread W of 75W early Fri through Sat morning. $$ Stripling