119 AXNT20 KNHC 131650 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Tue Aug 13 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 1200 UTC surface analysis and satellite imagery through 1700 UTC. ...SPECIAL FEATURES... Tropical Storm Ernesto is centered near 16.9N 62.6W at 13/1500 UTC or 130 nm ESE of St. Croix, moving WNW at 16 kt. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Maximum estimated seas are near 15 ft. Estimated minimum central pressure is 1003 mb. Bands of moderate to strong showers and thunderstorms continue to increase surrounding Ernesto, and are moving across the Leeward Islands and eastern Caribbean at this time. Scattered to numerous moderate to strong convection is seen on satellite imagery from 11N to 20N between 58W and 66W. Ernesto is expected to continue moving west- northwestward through tonight. A motion toward the northwest and then north at a slower forward speed is expected on Wednesday and Thursday. On the forecast track, the center of Ernesto should pass near or over the Virgin Islands this evening, and then pass just to the northeast and north of Puerto Rico tonight and on Wednesday. Ernesto should then move over the western Atlantic later in the week. Additional strengthening is forecast, and Ernesto is expected to become a hurricane by early Wednesday. Tropical Storm Ernesto is expected to produce total rain accumulations of 4 to 6 inches over portions of the Leeward Islands from Guadeloupe to Dominica and across the U.S and British Virgin Islands. Rainfall 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 in areas of the Leeward Islands through today, and over the Virgin Islands into Puerto Rico by later today through Wednesday. Storm surge and very large surf produced by swell from Ernesto will impact Puerto Rico and the Virgin Islands tonight through early Wed, producing life threatening conditions along the coasts. Please read the latest HIGHSEAS 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. ...TROPICAL WAVES... The axis of an eastern Atlantic tropical wave is along 30W, from 05N to 20N. It is moving west around 10 kt. Scattered showers are seen near far southern portions of the wave, from 05N to 09N between 24S and 35W. The axis of a tropical wave is near 91W from 12N to 20N, cutting across areas from the far Eastern Pacific across Guatemala, the western Yucatan Peninsula, and into the southeastern Bay of Campeche. Scattered moderate isolated strong convection is noted generally from 15N to 20N between 81W and 88W, extending to the coasts of Mexico, Belize, Guatemala, and Honduras. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic off the northern coast of Mauritania near 21N17W and extends southwestward to near 09N45W. Scattered to numerous moderate to strong convection is noted from 03N to 11N and E of 20W to the coast of Africa, and from 07N to 13N between 40W and 48W. ...GULF OF MEXICO... Scattered moderate convection is drifting westward across the Bay of Campeche and across the SW Gulf south of 25N and west of 90W. This convection is in association with a surface trough that has been moving slowly westward across the area. More scattered showers and isolated thunderstorms are developing generally along 24N due to an area of convergent easterly flow at the surface. Scattered moderate convection is also noted along and within 60nm south of the Louisiana and Mississippi coastlines, likely associated with a weak stationary front inland over the SE US. Otherwise, a weak pressure gradient is supporting light to gentle winds over much of the basin with seas 2 to 4 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 fresh winds are expected along the Yucatan Peninsula this evening. ...CARIBBEAN SEA... Please see the Special Features section above for more information on Tropical Storm Ernesto. Scattered moderate convection occurring ahead of Ernesto has passed south of Puerto Rico and reached as far west as 73W. Fresh to strong strong NE winds are spreading westward across the NE Caribbean ahead of Ernesto, where seas are building to 5 to 8 ft. Away from Ernesto, scattered moderate convection is occurring in the SW Caribbean generally west of 80W and south of 15N to the coasts of Nicaragua, Costa Rica, and Panama. Gentle to moderate winds prevail across most of the central Caribbean, where seas are in the 4 to 7 ft range. Moderate to fresh winds are noted via satellite scatterometer data through the Mona Passage and south of Hispaniola. Gentle to moderate winds and seas of 3 to 5 ft are in the both the SE and western Caribbean. For the forecast, Ernesto will move to near 18.0N 64.6W this evening with maximum sustained winds 55 kt gusts 65 kt, then strengthen to a hurricane near 19.8N 66.6W Wed morning with maximum sustained winds 65 kt gusts 80 kt. Ernesto is forecast to move to near 22.0N 68.0W Wed evening with maximum sustained 75 kt gusts 90 kt, to near 24.3N 68.5W Thu morning with maximum sustained winds 85 kt gusts 105 kt, then turn northward and continue to gradually strengthen as it moves around 10 kt across the western Atlantic. High pressure will gradually build westward along 20N late Fri through Sat in its wake. ...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 23.5N. This has produced a large wave field moving in synch with Ernesto, with seas of 8 to 12 ft in E swell extending from 14N to 24N between 54W and 66W. Away from Tropical Storm Ernesto, an area of scattered showers and isolated thunderstorms is observed via satellite over the northern Bahamas, the Straits of Florida, and the northern coast of Cuba. Otherwise, high pressure prevails across the tropical and subtropical waters N of 20N, anchored by a 1024 mb high centered near 35N34W. A ridge extends from the high center W-SW along 29N/30N, 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 moderate to fresh, locally strong NE winds and seas of 6 to 8 ft near the Canary Islands. S of 20N, gentle to moderate winds and seas of 4-7 ft prevail. For the forecast west of 55W, a broad ridge, currently extending from the central Atlantic W-SW to central Florida, will shift E and weaken over the next few days. Ernesto will move to near 18.0N 64.6W this evening with maximum sustained winds 50 kt gusts 60 kt, then strengthen to a hurricane near 19.8N 66.6W Wed morning with maximum sustained winds 65 kt gusts 80 kt, move to near 22.0N 68.0W Wed evening with maximum sustained 75 kt gusts 90 kt, to near 24.3N 68.5W Thu morning with maximum sustained winds 85 kt gusts 105 kt, to near near 26.3N 68.1W Thu evening with maximum sustained winds 90 kt gusts to 110 kt and to near 28.2N 67.0W Fri morning with maximum sustained winds 95 kt gusts 115 kt. Ernesto will change little in intensity as it moves to just north of the area to near 31.4N 65.2W early Sat and to well north of the area during Sat night. High pressure will gradually build westward along 20N late Fri through Sat in its wake. $$ Adams