000 AXNT20 KNHC 252305 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Tue Sep 26 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 2200 UTC. ...SPECIAL FEATURES... Tropical Storm Philippe is centered near 17.3N 46.7W at 2100 UTC, or 1080 nm E of the Northern Leeward Islands, moving W at 13 kt. Maximum sustained winds are 40 kt gusting to 50 kt. Estimated minimum central pressure is 1002 mb. Peak seas are near 20 ft. Westerly upper level wind shear continues to displace the associate deep convection to the east of the center this afternoon. Scattered to numerous moderate to strong convection is seen from 90 to 420 nm east of the center between 15N and 20N. A turn to the west-northwest is expected by tonight, and a northwestward motion is forecast to occur in a couple of days. Little change in strength is forecast during the next few days as Philippe remains in a sheared environment. 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. Eastern Tropical Atlantic (AL91): A tropical wave located several hundred miles west-southwest of the Cabo Verde Islands, along 32-33W, and continues to produce disorganized showers and thunderstorms. Maximum sustained winds are estimated at 20 kt and peak seas to 9 ft. Scattered to numerous moderate to strong convection is noted from 06N-14N between 28W-38W. Environmental conditions are forecast to be conducive for gradual development, and a tropical depression is likely to form within the next few days as the system moves west-northwestward across the central tropical Atlantic. There is a medium chance of formation through 48 hours. ...TROPICAL WAVES... An east Atlantic tropical wave - Invest AL91 - has its axis along 32-33W between 03N-17N, moving westward at 10-15 kt. See SPECIAL FEATURES above for more information. A central Caribbean tropical wave has its axis along 79W, south of 19N, moving westward at 10-15 kt. Numerous moderate and scattered strong convection is noted from 10N-19N between 77W- 82W. ...MONSOON TROUGH/ITCZ... The monsoon trough leaves the coast of Senegal near Dakar and continues to 09.5N24W to 1010 mb low pressure (AL91) near 10.5N32.5W and then to 06.5N42W. The monsoon trough begins again at 15N48W to 10N53W, where the ITCZ then extends W-SW to the coast of Venezuela near 09N61.5W. Scattered moderate and isolated strong convection is noted from 04N-11.5N between 14W-21W and from 08.5N-12.5N between 46W-61W. Scattered moderate convection is noted from 10N-14N east of 20W. ...GULF OF MEXICO... A surface trough extends from the Yucatan peninsula near 21N89W north-northeastward to 28.5N85W. Widely scattered moderate convection is noted across the waters of the Florida Big Bend, and south of south of 24.5N between 83W and 89W. The surface trough and convection are being forced by a deep-layered upper trough over the same location. Moderate winds surround the northern periphery of the trough, where seas are 3-4 ft. Winds removed from any thunderstorms are light to gentle with seas 2-3 ft. For the forecast, the surface trough over the southeast and south-central Gulf accompanied by scattered showers and thunderstorms will drift slowly westward, and into the western Gulf through mid week and dissipate. 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. Winds may increase over the northern Gulf the end of the week into the weekend. ...CARIBBEAN SEA... The Bermuda-Azores High located well north of the Caribbean is interacting with the 1008 mb Colombian Low to produce generally fresh trades over the central Caribbean, and southwest of Jamaica, while gentle to moderate prevail elsewhere. Seas are 5-8 ft over the central Caribbean and SW of Jamaica, and 3-4 ft elsewhere. Numerous moderate and scattered strong convection is noted from 10N-19N between 77W-82W in association with the tropical wave, while scattered moderate isolated strong convection extends from the NE coast of Honduras northward to the W coast of Cuba. Winds and seas are higher in association with this thunderstorm activity. In the forecast, high pressure north of the area will continue to support moderate to fresh trade winds across most of the eastern and central Caribbean into mid 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 late Tue, ahead of Tropical Storm Philippe. Philippe is expected to turn NW before reaching 55W, and move into the central Atlantic. Scattered deep convection associated with the interaction of the tropical wave and deep layered low pressure across the southeast Gulf of Mexico and the Yucatan Peninsula will shift westward through Wed. ...ATLANTIC OCEAN... Refer to the SPECIAL FEATURES section for details on Tropical Storm Philippe and Invest AL91. An expansive Bermuda-Azores High and associated ridge extends just north of our waters, to the east of 64W. Aside from higher winds near Philippe and Invest AL91, the trades are generally gentle to moderate, with seas 6-8 ft in the central and eastern Atlantic and light to gentle, with seas 4-6 ft in the western Atlantic. A surface trough extends from 25N65W to 28N63W with scattered moderate convection within 120 NM east of the trough axis, but no enhancement of winds or seas. Moderate to fresh trades prevail E of 35W to offshore of Africa, with seas generally 6 to 7 ft. Philippe will move to 17.7N 48.5W Tue morning, to near 18.4N 50.4W Tue afternoon, to near 19.3N 52.3W Wed morning, to near 20.4N 54.0W Wed afternoon, to near 21.6N 55.4W Thu morning, and near 22.2N 56.3W Thu afternoon. Philippe will change little in intensity as it moves to near 22.9N 57.7W Fri afternoon. Regardless of the exact position of the center later in the week, rough seas ahead of the storm can be expected east of 60W starting late Tue. Elsewhere, seas will build by Thu north of the Bahamas and east of Florida in NE swell mixing with ESE from from Philippe. $$ Stripling