000 AXNT20 KNHC 271119 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Wed Sep 27 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 0600 UTC surface analysis and satellite imagery through 1100 UTC. ...SPECIAL FEATURES... Tropical Storm Philippe is centered near 17.6N 52.7W at 27/0900 UTC, or 595 nm E of the northern Leeward Islands, moving W at 10 kt. Estimated minimum central pressure is 1003 mb. Maximum sustained winds are 40 kt with gusts to 50 kt. Peak seas are 18 to 19 ft near and just northeast of the center. The radius of 12 ft or greater seas extends outward to 300 nm from the center in the N semicircle. Scattered to numerous moderate with scattered strong convection is occurring within 360 nm of the center in the E semicircle and 120 nm NW quadrant. Philippe continues to struggle due to strong southwesterly shear. A west to west-northwest motion and a gradual weakening trend are expected during the next few days. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center, at the website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Gale Warning Associated with Invest Area (AL91): A central Atlantic tropical wave is near 42W from 17N southward through a 1007 mb low (AL91) at 11N42W, and moving west at 15 kt. Scattered moderate to isolated strong convection is seen within 270 nm of the center in the northern semicircle. A large area of fresh to near-gale force E to SE winds with 8 to 11 ft seas are present from 09N to 20N between 36W and 45W. Environmental conditions are forecast to be conducive for development, and a tropical depression or storm is expected to form in the next day or so while the system moves west-northwestward across the central tropical Atlantic. The chance of development within the next 48 hours is high. Gale force winds are forecast to develop with this low pressure near 13N44.5W this evening. 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 Tropical Weather Outlook at hurricanes.gov for more information. ...TROPICAL WAVES... A western Caribbean tropical wave is near 85W from 19N southward across Central America and into the East Pacific. It is moving west at 10 kt. Aided by mid-level diffluent flow, scattered showers and thunderstorms are occurring from 15N to 22N between 80W and 88W, with the strongest convection located between the Isle of Youth and the western tip of Cuba. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic along the Mauritania coast near 18N16W to 09N20W to 07N32W. Scattered moderate convection is noted from 07N to 12N between 23W and 31W. ...GULF OF MEXICO... A broad surface trough extends southwestward from Destin, Florida to the eastern Bay of Campeche. Isolated thunderstorms are occurring across the northern Gulf. Another surface trough runs southwestward from northeastern Florida to Sarasota, Florida to 25N83.5W. Scattered moderate isolated strong convection is noted from the Yucatan Channel northeastward to the Ft. Myers, FL area. Moderate SE winds and seas of 2 to 4 ft are noted in the southeastern Gulf, including the Yucatan Channel and Straits of Florida. Gentle winds and 1 to 3 ft seas prevail for the rest of the Gulf. For the forecast, the broad surface trough will drift slowly W through tonight before dissipating. Scattered showers and isolated thunderstorms are expected to the east of the trough, over the eastern half of the Gulf, through tonight. Meanwhile, gentle to moderate NE to E winds and slight seas will prevail across the basin through early Thu. Winds are forecast to increase over the northern Gulf the end of the week into the weekend as high pressure ridging strengthens over the southeastern United States. ...CARIBBEAN SEA... An upper-level low over the eastern Caribbean Sea is producing scattered to numerous thunderstorms from 13N to 18N between 60W and 66W, including over the Lesser Antilles. Thunderstorms are also seen north of Jamaica. Moderate to fresh trades and 4-6 ft seas prevail over the central Caribbean. Gentle to moderate trades and 3-5 ft seas prevail elsewhere. For the forecast, Tropical Storm Philippe will move to near 19.5N57W Thu afternoon, weaken to a tropical depression near 19.5N60W Fri afternoon, and weaken to a remnant low near 19.5N62W early Sat morning. Seas are building across the waters east of the Leeward Islands ahead of Tropical Storm Philippe. High pressure north of the area will support moderate to fresh trade winds across most of the eastern and central Caribbean through tonight. Winds across the Caribbean Sea will then diminish late this week into this weekend. ...ATLANTIC OCEAN... Refer to the SPECIAL FEATURES section above for details on Tropical Storm Philippe and a Gale Warning related to Invest AL91. Convergent southeasterly winds to the east of a surface trough over Florida are triggering scattered showers and isolated thunderstorms from the northwest Bahamas northward to beyond 31N, mainly west of 74W. The Atlantic ridge associated with the Bermuda and Azores Highs is supporting light to gentle winds north of 26N between 30W and the Florida coast. Seas are 3-5 ft west of 65W and north of 25N. South of 25N and west of 65W, moderate trades and 4-6 ft seas prevail. From 26N to 31N and between 30W and 65W, seas are 5 to 7 ft in mixed swell. Fresh to locally strong NE trades and 6 to 10 ft seas prevail in between the Canary Islands and Cabo Verde Islands. Strong winds and rough seas associated with Tropical Storm Philippe and Invest AL91 are occurring from 10N to 25N between 36W and 59W. For the forecast west of 55W, Tropical Storm Philippe will move to near 19.5N57W Thu afternoon, weaken to a tropical depression near 19.5N60W Fri afternoon, and weaken to a remnant low near 19.5N62W early Sat morning. Rough seas ahead of the storm have moved W of 55W, and will continue to spread east of 65W through the end of the week. Elsewhere, seas will build tonight and Thu north of the Bahamas and east of Florida in NE swell. $$ Hagen