000 AXNT20 KNHC 151758 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 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 1200 UTC surface analysis and satellite imagery through 1700 UTC. ...SPECIAL FEATURES... Tropical Storm Fiona is centered near 16.6N 54.3W at 15/1500 UTC or 430 nm E of the Leeward Islands and moving W at 12 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained winds are 45 kt with gusts to 55 kt. Seas are currently peaking at 20 to 22 ft near and northeast of the center. Numerous moderate convection is noted just east and southeast of the center from 15N to 18N between 51W and 53W. Some slight strengthening is possible with Fiona during the next few days. Fiona will move westward with a slight decrease in forward speed through late Sat, then turn toward the west-northwest on Sun. This will bring Fiona across the northern Leeward Islands late Fri night and early Sat, near the Virgin Islands and Puerto Rico late Sat into Sun, and then near eastern Hispaniola on Mon. Fiona is expected to produce heavy rainfall that could lead to flash and urban flooding, along with isolated mudslides in higher terrains across the aforementioned locations. Swells generated by Fiona are expected to begin affecting the northern Leeward Islands by early Friday. These swells could cause life-threatening surf and rip current conditions. Please consult products from your local weather office. 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 is near 18W from just south of Dakar at 14N southward, and moving W around 15 kt. Scattered moderate convection is noted from 06N to 12N between 18W and 24W. A central Atlantic tropical wave is near 34W from 20N southward, and moving W at 10 to 15 kt. Scattered moderate convection is observed from 16N to 19N between 30W and 37W. A western Caribbean tropical wave is near 80W from southern Cuba southward to Panama, and moving W around 10 kt. Scattered showers and isolated thunderstorms are occurring from western Cuba southward to near the Honduras-Nicaragua border. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic along the African coast near the Mauritania-Senegal border, passing south of the Cabo Verde Islands at 13N24W to 16N39W. Scattered showers are found well south of the trough from 01N to 03N between 15W and 18W, and along the Sierra Leone/Liberia coast. There is no ITCZ present based on the latest analysis. The eastern end of the East Pacific monsoon trough is triggering scattered showers and thunderstorms over the southwestern Caribbean Sea. ...GULF OF MEXICO... A stationary front extends westward from just north of Tampa, FL to southwest of New Orleans, LO. Scattered showers and thunderstorms are noted up to 60 nm along either side of the front. Surface troughing is generating similar weather along the western and southeastern Gulf, including the Yucatan Channel. Moderate ENE to E winds and seas of 2 to 4 ft are present across the northern Gulf, north of 28N. Gentle to moderate E to SE winds and 1 to 3 ft seas prevail for the rest of the Gulf. For the forecast, the stationary front will gradually dissipate by the weekend. High pressure will build over the southeast U.S. in the wake of the front, maintaining gentle to moderate easterly breezes and slight seas through early next week. ...CARIBBEAN SEA... Tropical Storm Fiona is forecast to impact the northeast Caribbean. Please refer to the Special Features Section for more details. Pressure gradient between the Bermuda High and Tropical Storm Fiona is creating a trad-wind surge at the northeastern basin, causing scattered showers and isolated thunderstorms near Puerto Rico, the Virgin and northern Leeward Islands. Refer to the Monsoon Trough/ITCZ and Tropical Waves sections for additional weather in the Caribbean Basin. Moderate with locally fresh ENE trades and seas of 4 to 7 ft are found over the northeastern and central basin. Gentle to moderate E to SE trades and 3 to 5 ft seas prevail for the rest of the basin. For the forecast, Tropical Storm Fiona will move to near 17N59W Fri morning, 17N63W Sat morning, 18N67W Sun morning, and 19.5N 68.5W Mon morning. Expect increasing winds and squalls over the northeastern Caribbean by Fri and into the weekend. Otherwise, moderate to fresh trades will prevail over the central Caribbean through Fri. ...ATLANTIC OCEAN... Tropical Storm Fiona is forecast to impact portions of the Atlantic and northeast Caribbean. Please refer to the Special Features Section for more details. A stationary front extends southwestward from a 1016 mb low off the Carolina coast across 31N77W to near Daytona Beach, FL. Farther south, a surface trough stretches southwestward from the same low across 31N76W to near Fort Pierce, FL. These features are producing scattered showers and thunderstorms from southern Florida/northwest Bahamas northeastward to beyond 31N76W. Refer to the Monsoon Trough/ITCZ and Tropical Waves sections for additional weather in the Atlantic Basin. The Atlantic ridge is supporting light to gentle winds and seas of 3 to 6 ft in residual northerly swell, north of 23N between the northwestern African coast and 70W. To the west, gentle to moderate SE to SW to NW winds and 4 to 5 ft seas are seen from the Bahamas northward between 70W and the Georgia/Florida coast. Outside the influence of Tropical Storm Fiona, gentle to moderate NE to E trades and seas at 4 to 7 ft exist from 10N to 23N between 40W and the Lesser Antilles, and near the Cabo Verde Islands from 15N to 23N between the central African coast and 40W. Light to gentle with locally moderate monsoonal and southerly winds with 4 to 6 ft seas in southerly swell prevail for the remainder of the Atlantic Basin. For the forecast west of 55W, Tropical Storm Fiona will move to near 17N59W Fri morning, 17N63W Sat morning, 18N67W Sun morning, and 19.5N 68.5W Mon morning. Expect increasing winds, seas and squalls near the path of Fiona. A stationary front is draped off the northeast Florida coast. Expect this front to linger near this area through most of the weekend, bringing moderate NE winds north of it along with showers and thunderstorms. $$ Chan