000 AXNT20 KNHC 282328 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Tue Aug 29 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 1800 UTC surface analysis and satellite imagery through 2300 UTC. ...SPECIAL FEATURES... Major Hurricane Franklin is centered near 28.5N 71.0W at 28/2100 UTC or 420 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 35 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. Franklin is a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Additional strengthening is possible, but gradual weakening is expected to begin late Tuesday. Swells, life-threatening surf and rip currents generated by Franklin are already affecting Bermuda and the coast of the southeast United States. These conditions are expected to spread northward along the east coast of the United States and Atlantic Canada during the next couple of days. Tropical Storm Idalia is centered near 21.4N 85.1W at 28/2100 UTC or 30 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 24 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 80W. 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 eastern Gulf of Mexico on Tuesday, and reach the Gulf coast of Florida within the Hurricane Warning area on Wednesday. Rapid strengthening is predicted during the next day or so. Idalia is forecast to become a hurricane this evening or tonight, and become a major hurricane by late Tuesday or Tuesday night. 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 and Idalia NHC Forecasts/Advisories and Public Advisories at www.hurricanes.gov for more details. ...TROPICAL WAVES... An eastern Atlantic tropical wave has its axis along 37W, south of 17N, 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 55W, south of 17N, moving westward at 10-15 kt. Scattered showers are noted in within 60 nm on either side of the wave axis. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic near 20N17W and continues southwestward to 07N42W. 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 over the Yucatan Channel. A stationary front is draped across the NW Gulf of Mexico producing a few showers. Meanwhile, a surface trough is analyzed in the eastern Gulf of Mexico generating scattered showers and isolated thunderstorms. Outer rainbands of Idalia are noted in latest satellite imagery off SW Florida. To the west, another surface trough is analyzed in the Bay of Campeche enhancing 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 will strengthen to a hurricane near 22.7N 85.2W Tue morning, move to 24.9N 85.0W Tue afternoon, 27.6N 84.4W Wed morning, inland to 30.4N 82.9W Wed afternoon, and weaken to a tropical storm near 32.7N 80.4W Thu morning. 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 over the Yucatan Channel. Outside of Idalia, high pressure aloft in the eastern and central Caribbean results in subsidence, keeping the region devoid of any deep convection. Moderate to 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 in the eastern and central Caribbean and slight in the SW Caribbean. For the forecast, Tropical Storm Idalia will strengthen to a hurricane over the Gulf of Mexico near 22.7N 85.2W Tue morning. As Idalia moves farther N into the Gulf of Mexico on Tue, conditions will improve in the NW Caribbean. High pressure will build westward across the western Atlantic through Thu as Hurricane Franklin lifts north of the region. This will lead to moderate to fresh trade winds in the eastern Caribbean by tonight, 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 1032 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 scattered moderate convection north of 20N and between 46W and 64W. 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 near gale northerly winds east of 25W and north of 16N. 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 28.5N 71.0W at 5 PM 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 29.7N 71.1W Tue morning, 31.3N 70.3W Tue afternoon, and will be N of area near 33.0N 68.8W Wed morning. Expect increasing winds and building seas E of Florida on Tue as Idalia moves across the Eastern Gulf of Mexico. Tropical Storm Idalia will strengthen to a hurricane near 22.7N 85.2W Tue morning, move to 24.9N 85.0W Tue afternoon, 27.6N 84.4W Wed morning, inland to 30.4N 82.9W Wed afternoon, move inland and weaken to a tropical storm near 32.7N 80.4W Thu morning, and 34.0N 76.8W Thu afternoon. Idalia will change little in intensity as it moves to near 34.1N 71.4W by Fri afternoon. $$ ERA