000 AXNT20 KNHC 281757 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Mon Aug 28 2023 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... Major Hurricane Franklin is centered near 28.1N 71.1W at 28/1800 UTC or 400 nm N of Grand Turk Island, moving N at 8 kt. Estimated minimum central pressure is 937 mb. Maximum sustained wind speed is 125 kt with gusts to 150 kt. Peak seas are currently around 33 ft. A well-defined eye is apparent in satellite imagery and numerous moderate to strong convection is evident within 75 nm of the center with numerous moderate elsewhere within 150 nm of the center. The northward to north-northeastward motion with a slightly faster forward speed is expected during the next few days. On the forecast track, the center of Franklin is expected to pass well to the west of Bermuda on Wednesday. Additional strengthening is possible today, but gradual weakening is expected to begin later Tuesday. Swells, life-threatening surf and rip currents generated by Franklin are beginning to affect Bermuda and the coast of the southeast United States and are expected to spread northward along the east coast of the United States and, Atlantic Canada during the next couple of days. 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 Franklin NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Tropical Storm Idalia is centered near 21.2N 85.1W at 28/1800 UTC or 40 nm SSW of the western tip of Cuba, moving N at 7 kt. Estimated minimum central pressure is 987 mb. Maximum sustained wind speed is 60 kt with gusts to 75 kt. Peak seas are currently around 22 ft. Numerous moderate to strong convection is evident within 135 nm in the SE semicircle and 45 nm in the NW semicircle. Scattered moderate convection is evident elsewhere within 210 nm in the SE semicircle and 90 nm in the NW semicircle. Additional deep convection is noted in a bands covering the NW Caribbean Sea, west of 81W. A northward motion is expected through tonight, followed by a faster north-northeast motion on Tuesday and Wednesday. On the forecast track, the center of Idalia is forecast to pass near or over western Cuba tonight, over the extreme southeastern Gulf of Mexico by early Tuesday, and reach the Gulf coast of Florida on Wednesday. Idalia is forecast to become a hurricane later today and a dangerous major hurricane over the northeastern Gulf of Mexico by early Wednesday. Heavy rainfall is expected across portions of western Cuba and may produce areas of flash and urban flooding as well as landslides across western Cuba. Areas of flash and urban flooding, some of which may be locally significant, are expected across portions of the west coast of Florida, the Florida Panhandle, and southern Georgia Tuesday into Wednesday, spreading into portions of the eastern Carolinas Wednesday into Thursday. 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 Idalia NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...TROPICAL WAVES... An eastern Atlantic tropical wave has its axis along 35W, south of 18N, moving westward at 15-20 kt. A few showers are noted near the southern portion of the trough axis. A central Atlantic tropical wave has its axis along 52W, south of 16N, moving westward at 10-15 kt. Scattered moderate to isolated strong convection is observed from 10N to 15N and between 50W and 56W. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through the coast of Mauritania near 19N16W and continues southwestward to 11N30W and 08N45W. Scattered moderate convection is evident from 04N to 10N and east of 30W. ...GULF OF MEXICO... Please read the SPECIAL FEATURES section for details about Tropical Storm Idalia, currently entering the Yucatan Channel. A weak stationary front is draped across the NW Gulf of Mexico producing a few showers. Meanwhile, a weak surface trough is analyzed in the eastern Gulf of Mexico generating some showers and isolated thunderstorms. An outer rainband of Idalia is seen on satellite imagery off SW Florida. Lastly, a weak surface trough in the Bay of Campeche allows for isolated to scattered shower activity. Moderate or weaker winds and slight seas prevail across most of the Gulf, except for the SE Gulf where Idalia is inducing stronger winds and higher seas. For the forecast, Tropical Storm Idalia is near 20.8N 85.2W at 11 AM EDT, and is moving north at 7 kt. Maximum sustained winds are 55 kt with gusts to 65 kt, and the minimum central pressure is 990 mb. Idalia will strengthen to a hurricane near 22.0N 85.2W this evening, move to 23.9N 85.1W Tue morning, 26.4N 84.6W Tue evening, 29.2N 83.5W Wed morning, move inland and weaken to a tropical storm near 31.9N 81.2W Wed evening, and 33.6N 78.0W Thu morning. Idalia will change little in intensity as it moves to near 34.6N 71.2W early Fri. High pressure and improving conditions will arrive in the wake of Idalia late in the week. ...CARIBBEAN SEA... Please read the SPECIAL FEATURES section for details about Tropical Storm Idalia, currently entering the Yucatan Channel. Outside of Idalia, high pressure aloft in the eastern and central Caribbean Sea results in subsidence, keeping the region devoid of deep convection. However, this pattern also allows for temperatures above normal. A heat advisory is in effect for portions of Puerto Rico. Moderate to locally fresh easterly trade winds were captured by a recent scatterometer satellite pass in the eastern and central Caribbean, while light to gentle winds prevail in the SW Caribbean. Seas are slight to moderate ft in the eastern and central Caribbean and slight ft in the SW Caribbean. For the forecast, Tropical Storm Idalia is near 20.8N 85.2W at 11 AM EDT, and is moving north at 7 kt. Maximum sustained winds are 55 kt with gusts to 65 kt, and the minimum central pressure is 990 mb. Idalia will strengthen to a hurricane near 22.0N 85.2W this evening, move to 23.9N 85.1W Tue morning, 26.4N 84.6W Tue evening, 29.2N 83.5W Wed morning, move inland and weaken to a tropical storm near 31.9N 81.2W Wed evening, and 33.6N 78.0W Thu morning. Idalia will change little in intensity as it moves to near 34.6N 71.2W early Fri. Other than Idalia, gentle to moderate winds will prevail across the basin E of 80W through early Mon. High pressure will build westward across the western Atlantic late Mon through Thu as Hurricane Franklin lifts north of the region. This will lead to moderate to fresh trade winds in the eastern Caribbean by Mon night, then in the central Caribbean by Tue, locally strong there. ...ATLANTIC OCEAN... Please read the SPECIAL FEATURES section for details about Hurricane Franklin and Tropical Storm Idalia. Outside of Franklin, a 1034 mb subtropical ridge positioned a few hundred miles to the northeast of the Azores dominates the eastern and central Atlantic. A couple of surface troughs are noted in the central Atlantic, producing isolated to scattered moderate convection north of 18N and between 47W and 65W. Latest satellite-derived wind data suggests that fresh to strong winds are present with the strongest convection. Moderate or weaker winds and slight to moderate seas are prevalent west of 25W. The pressure gradient between the aforementioned high pressure and lower pressures in NW Africa result in fresh to gale-force northerly winds east of 25W and north of 16N. The gale-force winds may be occurring in the water passages of the Canary Islands based on a scatterometer satellite pass from a few hours ago. Seas in these waters are 6-10 ft. Elsewhere, moderate or weaker winds and slight to moderate seas prevail. For the forecast W of 55W, Hurricane Franklin is near 27.8N 71.0W at 11 AM EDT, and is moving north at 8 kt. Maximum sustained winds are 125 kt with gusts to 150 kt, and the minimum central pressure is 937 mb. Franklin will move to 29.0N 71.2W this evening, 30.7N 70.8W Tue morning, and N of the forecast region near 32.5N 69.6W Tue evening. Then, Franklin will continue to move northward away from the area. Meanwhile, Tropical Storm Idalia is near 20.8N 85.2W at 11 AM EDT, and is moving north at 7 kt. Maximum sustained winds are 55 kt with gusts to 65 kt, and the minimum central pressure is 990 mb. Idalia will strengthen to a hurricane near 22.0N 85.2W this evening, move to 23.9N 85.1W Tue morning, 26.4N 84.6W Tue evening, 29.2N 83.5W Wed morning, move inland and weaken to a tropical storm near 31.9N 81.2W Wed evening, and 33.6N 78.0W Thu morning. Idalia will change little in intensity as it moves to near 34.6N 71.2W early Fri. Expect increasing winds and seas offshore of central and northern Florida with the passage of Idalia. $$ DELGADO