000 AXNT20 KNHC 150417 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Thu Sep 15 2022 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 0000 UTC surface analysis and satellite imagery through 0410 UTC. ...SPECIAL FEATURES... Recently upgraded Tropical Storm Fiona was centered near 16.7N 52.0W at 15/0300 UTC or about 650 nm E of the Leeward Islands moving WNW at 14 kt. Estimated minimum central pressure is 1002 mb. The maximum sustained wind speed is 45 kt with gusts to 55 kt. The maximum significant wave height is 14 ft and 12 ft seas extend up to 105 nm in the NE and NW quadrant, and 30 nm in the SE quadrant. Tropical Storm watches have been issued for portions of the Leeward Islands. Fiona is forecast to move through the Leeward Islands late Friday and be near the Virgin Islands, Puerto Rico and the Dominican Republic this weekend. Expect total rainfall accumulation of 3 to 5 inches with localized areas up to 8 inches across these islands. Due to a marginal environment, additional strengthening of storm will likely be slow to occur during the next day or so, but the intensity forecast remains uncertain. 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 T.S. Fiona NHC Forecast/Advisory and Public Advisory at https://www.nhc.noaa.gov/text/MIATCMAT2.shtml for more details. ...TROPICAL WAVES... An eastern Atlantic tropical wave extends along 15W, from 02N to 15N, moving W at 10 kt. Isolated moderate convection is observed from 02N to 12N, between 12W and 27W. An eastern Atlantic tropical wave extends along 32W, from 05N to 20N, moving W at 5 kt. Scattered moderate convection is observed from 15N to 19N, between 30W and 33W. A Caribbean tropical wave extends along 78W, from Panama to Cuba, moving W at 10 kt. Scattered moderate convection is observed from 11N to 13N, between 77W and 83W. Widely isolated and weak convection is noted elsewhere in the central and NW Caribbean. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Senegal near 15N17W to 07N41W. Associated convection is isolated and weak. ...GULF OF MEXICO... A stationary front extends across the northern Gulf, from Crystal River, FL to 28N91W. Scattered showers and thunderstorms are noted along this boundary. Widely isolated showers and thunderstorms are also observed throughout the basin. Outside of convection, gentle to moderate easterly trade winds dominate with 1-3 ft seas. For the forecast, The stationary front will gradually dissipate by the weekend. High pressure will build over the southeast U.S. following the front, maintaining gentle to moderate easterly breezes and slight seas into the weekend. ...CARIBBEAN SEA... Tropical Storm Fiona is forecast to impact the Leeward Islands late Friday and Friday night, and be near the Virgin Islands, Puerto Rico and the Dominican Republic this weekend. Please, refer to the Special Features Section for more details. The gradient between subtropical high pressure and lower pressure over the SW Caribbean is supporting moderate to fresh easterly flow across the majority of the basin. Seas are 3-5 ft in the eastern Caribbean, 4-6 ft in the central Caribbean, and 2-4 ft in the NW Caribbean. For the forecast, Tropical Storm Fiona is near 16.7N 52.0W 1002 mb at 11 PM EDT moving WNW at 14 kt. Maximum sustained winds 45 kt gusts 55 kt. Fiona will move to 16.9N 53.8W Thu morning, 17.1N 56.3W Thu evening, 17.2N 58.9W Fri morning, 17.3N 61.5W Fri evening, 17.6N 63.8W Sat morning, and 17.8N 65.8W Sat evening. Fiona will move inland over 18.7N 68.6W by late Sun. Expect increasing winds and squalls over the NE Caribbean by Fri and into the weekend. Otherwise, winds and seas will slightly increase tonight over the central Caribbean as high pressure builds north of the area in the wake of a tropical wave. Northerly swell moving through the Atlantic passages will gradually subside through tonight. ...ATLANTIC OCEAN... Tropical Storm Fiona is forecast to impact the Leeward Islands late Friday and Friday night, and be near the Virgin Islands, Puerto Rico and the Dominican Republic this weekend. Please, refer to the Special Features Section for more details. Outside of impacts from Tropical Storm Fiona, the Atlantic basin is predominately under the influence of high pressure. In the western Atlantic, a stationary boundary and surface trough are causing scattered moderate convection from 22N to 31N, between 72W and 81W. Outside of thunderstorm activity, winds are generally gentle to moderate with 3-5 ft seas. Another stationary boundary in the central Atlantic extends from 31N39W to 27N51W. Winds are gentle to moderate with 5-7 ft seas in a northerly sell. In the eastern Atlantic, moderate NE winds and 5-7 ft seas dominate. For the forecast west of 55W, Tropical Storm Fiona is near 16.7N 52.0W 1002 mb at 11 PM EDT moving WNW at 14 kt. Maximum sustained winds 45 kt gusts 55 kt. Fiona will move to 16.9N 53.8W Thu morning, 17.1N 56.3W Thu evening, 17.2N 58.9W Fri morning, 17.3N 61.5W Fri evening, 17.6N 63.8W Sat morning, and 17.8N 65.8W Sat evening. Fiona will move inland over 18.7N 68.6W by late Sun. Expect increasing winds, seas and squalls near the cyclone over the next few days. A cold front may move into the waters off northeast Florida and stall by the end of the week into the weekend. $$ Flynn