465 AXNT20 KNHC 151020 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Thu Aug 15 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 0930 UTC. ...SPECIAL FEATURES... ...Hurricane Ernesto... Hurricane Ernesto is centered near 23.3N 69.1W at 0900 UTC or about 635 nm SSW of Bermuda, moving NNW at 11 kt. Estimated minimum central pressure is 979 mb. Maximum sustained wind speed is 75 kt with gusts to 90 kt. The satellite presentation of Ernesto continues to improve this morning, with large bands of convection spiraling completely around the center, with the center of Ernesto embedded in a deep convective central ball. Scattered to numerous moderate to strong convection prevails from 20N to 27N between 64W and 71W. Seas of 12 ft or greater are within 210 nm NE, 240 nm SE, 150 nm SW, and 165 nm NW quadrants, with seas to 34 ft. Swells generated by Ernesto are affecting portions of the northern Leeward Islands, the Virgin Islands, Puerto Rico, the Dominican Republic, the Turks and Caicos Islands, and the southeastern Bahamas. These swells will spread west through north and reach the Bahamas today, and reach Florida, the southeastern U.S. and Bermuda by Friday. These swells will produce large surf and lead to life- threatening rip current conditions. Please consult products from your local weather office for more details. 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. ...TROPICAL WAVES... The axis of an eastern Atlantic tropical wave is along 38W-39W from 04N to 18N, moving west at 10 kt. This wave is embedded in a broad area of Saharan Air. No significant convection accompanies this wave. A central Atlantic tropical wave is along 52W from 06N to 16N, moving west at around 15 kt. Scattered moderate to strong convection is noted from 11.5N to 14N between 51W and 55W. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic off the coast of Africa near 19.5N16W and extends southwestward to 11N32W to 13N47W. Scattered moderate to strong convention is noted from 05N to 12.5N between 17W and 28W. Scattered moderate isolated strong convection is noted within 60 nm either side of a line from 08N27W to 11.5N40W. ...GULF OF MEXICO... Scattered moderate isolated strong convection is noted over the Bay of Campeche, south of 21.5N, and to the W of surface trough from the Yucatan Peninsula into the eastern Bay of Campeche. To the NE, a stationary front extends across Northern Florida W-NW across the Big Bend to the western Florida Panhandle. A few showers are along this boundary E of 85W. Elsewhere, weak high pressure over the NE Gulf 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, the weak surface ridge will maintain gentle to moderate winds and slight to moderate seas across most of the basin into early next week. High pressure will build modestly across the NE Gulf Fri through Sat as the weak frontal boundary drifts south, and produce moderate easterly winds and a mild increase in seas. Otherwise, moderate to locally fresh winds, and scattered showers and thunderstorms are expected along the Yucatan Peninsula each evening through the period. ...CARIBBEAN SEA... Please see the Special Features section above for more information on Hurricane Ernesto. Strong convection affecting portions of Hispaniola and the Mona Passage earlier tonight has shifted NE and out of the area. Overnight scatterometer data depicted fresh to strong S to SE winds over the E Caribbean east of 70W, while light to gentle NE winds prevail elsewhere across the basin. Seas of 5 to 7 ft continue across the eastern basin, and up to 8 ft in the Mona Passage. Moderate seas prevail E of 77W, and slight seas prevail W of 77W. For the forecast, Hurricane Ernesto is forecast to continue to strengthen as it moves in a northerly motion at around 10 kt over the western Atlantic through the end of the week, passing very near Bermuda on Sat morning. In its wake, high pressure will gradually build westward along 22N late Fri into early next week, bringing a return to a more typical trade wind flow across the basin. A tropical wave along 52W is accompanied by scattered thunderstorms and gusty winds. This wave will move across the Tropical N Atlantic waters this evening through tonight, and into the eastern Caribbean Fri while weakening. ...ATLANTIC OCEAN... Please see Special Features section above for more information about Hurricane Ernesto. A broad wind surge has accompanied Ernesto for the past few days, with fresh to strong winds north of the storm extending to 27N. This has produced a large wave field moving in synch with Ernesto, with seas of 8 to 12 ft, and higher near Ernesto, extending from 19N to 28N between 63W and the southeast Bahamas along 74W. Away from Ernesto, a weak frontal boundary extends from near Bermuda to north-central Florida. Scattered moderate convection is wihtin 90 nm south of this boundary. High pressure prevails across the tropical and subtropical waters N of 23N, anchored by a 1025 mb high centered near 37N32W that extends a ridge to 27N57W then very weakly north of Ernesto. Light to gentle winds prevail across the central and E Atlantic between 39W-60W. Moderate to fresh E to NE winds and slight seas prevail over much of the waters elsewhere E of 39W, except for strong to near gale NE winds and rough seas near the Canary Islands and near the coast of Morocco. S of 20N, Gentle to locally moderate winds and slight seas prevail. For the forecast west of 55W, Hurricane Ernesto is forecast to continue to strengthen as it moves on a northerly track, reaching near 25.4N 69.1W this afternoon, near 29.3N 66.7W Fri afternoon, then pass very near Bermuda Sat morning. A weak frontal boundary extends from near Bermuda to north-central Florida and will drift southward across the northwestern part of the area, 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 today through Fri night before subsiding Sat through Sun. $$ Stripling