000 AXNT20 KNHC 242357 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Mon Sep 25 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 2230 UTC. ...SPECIAL FEATURES... The center of Tropical Storm Philippe is located near 16.8N 42.5W at 5 PM EDT, moving west-northwest at 10 kt. Maximum sustained winds are 45 kt with gusts to 55 kt. Minimum central pressure is 1000 mb. Peak seas near the center are up to 20 ft. Numerous moderate scattered strong convection is noted within 270 nm across the eastern semicircle and 75 nm across the western semicircle. A continued west-northwest motion is expected for the next 24 to 36 hours before the ridge to the north weakens and allow Philippe to move more northwest by mid-week. Gradual strengthening is expected at it begins to move northwestward. Please, read the latest HIGH SEAS FORECAST, that is issued by the National Hurricane Center, at the website- https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml, and the latest Tropical Storm Philippe NHC Forecast/Advisory and Public Advisory, at www.hurricanes.gov, for more details. ...TROPICAL WAVES... An eastern Atlantic tropical wave has its axis along 26.5W, south of 19N, moving westward at 10 kt. Scattered moderate isolated strong convection is observed from 04.5N to 13.5N and between 25W and 35W. The environmental conditions are forecast to be conducive for gradual development of this system, and a tropical depression may form around midweek. This weather system is forecast to move westward to west-northwestward in the central tropical Atlantic Ocean. An eastern Caribbean tropical wave has its axis along 72W, south of 19N, moving westward at 10 to 15 kt. Scattered moderate convection is noted across coastal Venezuela at the base of the tropical wave. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through the coast of Senegal near 12.517W to 1010 mb low pres near 08.5N26.5W to 11N37W. Isolated clusters of moderate convection are noted from 04N to 07N between 16W and 20W. Scattered moderate isolated strong convection is noted from 08.5N to 15N between 49W and 61W. ...GULF OF MEXICO... Weak ridging extends across the northern Gulf from 1015 mb high pressure along the coast of the Florida Panhandle. Farther south, an inverted trough extends from 27N87W to the NE Yucatan Peninsula. An upper level cyclone across this same area is supporting scattered moderate to strong convection to the south of 27N, and from 84W to the Florida coastal waters, and continuing eastward across the Straits of Florida to 78W. This pattern is supporting moderate NE winds across northern portions of the trough where altimeter data shows seas 4 to 5 ft. Elsewhere across the basin, gentle breezes and slight seas prevail, outside of the active convection. For the forecast, the surface trough over the eastern Gulf will drift slowly into the western Gulf through the early part of the week and dissipate. Active convection will continue E of this trough through late Mon. Meanwhile, weak high pressure will persist over the north-central and northeast Gulf. This pattern will support gentle to moderate NE to E winds and slight seas across the basin through the middle of the week. ...CARIBBEAN SEA... The upper level cyclone across the eastern Gulf extends cyclonic flow southward across the Yucatan Channel to the Gulf of Honduras. Divergence aloft associated with this features is supporting scattered showers and thunderstorms across the northwest Caribbean to the west of 83W and across western Cuba. Thunderstorms are also active between 12N and the monsoon trough off Colombia. Late morning scatterometer data indicated moderate to fresh trade winds over the eastern and central Caribbean, with and behind the tropical wave. Seas are 5 to 7 ft there. Gentle breezes and slight seas are noted elsewhere. For the forecast, high pressure north of the area will support moderate to fresh trade winds across most of the eastern and central Caribbean through the early part of the week, with fresh to strong pulses off northwest Venezuela and northeast Colombia during mainly the overnight and early morning hours. Seas will build in mixed NE and E swell across the waters east of the Leeward Islands starting Mon, ahead of Tropical Storm Philippe. Philippe is expected to turn NW before reaching 60W, and move into the central Atlantic. ...ATLANTIC OCEAN... Refer to the Special Features section for details on Tropical Storm Philippe. Scattered showers and thunderstorms are noted across the Bahamas and Straits of Florida south of 26N associated with a weakening low level trough. Similar convection extends northward from 23N to 30N between 69W and 72W. Farther east, scattered showers and thunderstorms are active near another deep layered trough along 61W, noted from 25N to 28N between 57W and 62W. Elsewhere outside of the immediate area of Philippe, weak high pressure is supporting gentle to moderate trade winds with 5 to 7 ft combined seas in mixed swell. For the forecast west of 55W, the trough over the southern Bahamas will move westward into Florida through tonight. Weak high pressure will build from the north-central Atlantic north of 28N in the wake of the trough. Looking ahead, seas will build in mixed NE and E swell across waters northeast of the Leeward Islands starting Mon, ahead of Tropical Storm Philippe. Low pressure moving off the eastern seaboard may bring fresh NE to E winds and building seas off northeast Florida the middle of the week. Philippe will move to 17.3N 44.1W Mon morning, 17.8N 46.4W Mon afternoon, 18.2N 48.6W Tue morning, 18.8N 50.4W Tue afternoon, 19.7N 52.0W Wed morning, and 21.0N 53.5W Wed afternoon. $$ Stripling