000 AXNT20 KNHC 051059 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Thu Oct 05 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 1045 UTC. ...SPECIAL FEATURES... Tropical Storm Philippe is centered near 24.8N 65.9W at 05/0900 UTC or 390 nm N of St. Thomas, moving N at 12 kt. Estimated minimum central pressure is 1004 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Peak seas are presently around 15 ft. Latest satellite imagery indicates that the overall structure is not well organized. Numerous strong convection is observed within 270 nm of center in the SE quadrant and within 210 nm of the center in the SW quadrant. Scattered moderate to isolated strong convection is NE of the center from 25N to 28N between 62W-68W. Philippe is forecast to pass near Bermuda on Fri, and approach eastern New England and Atlantic Canada on Sat. Gradual strengthening is forecast during the next few days. Philippe is then forecast to become a Post- Tropical Cyclone on Sat as it approaches Atlantic Canada and New England. Rainfall will begin to affect Bermuda today with rainfall totals of 3-5 inches expected through Fri. These rainfall amounts could result in scattered flash flooding. Swells generated by Philippe will affect portions of the Atlantic coasts of the northern Leeward Islands, the Virgin Islands, and Puerto Rico for another day or so. Large swells are already affecting Bermuda from another weather system but will begin to increase further later today as Philippe approaches the island. These conditions are likely to cause life-threatening surf and rip currents. Please consult products from your local weather office. 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 Philippe NHC Forecast/Advisory and Public Advisory, at www.hurricanes.gov for more details. ...TROPICAL WAVES... An eastern Atlantic tropical wave has its axis near 34W from 03N to 14N. It is moving westward at around 15 kt. Numerous moderate to isolated strong convection is within 240 nm east of the wave from 07N to 10N. A western Atlantic tropical wave has its axis near 58W south of 17N, moving westward at around 15 kt. Scattered moderate convection is within 120 nm west of the wave from 08N to 12N. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends from 18N16W southwestward to 10N26W and to 07N41W, where latest scatterometer data indicates that it transitions to the ITCZ to 07N48W and to 08N54W. Numerous moderate to isolated strong convection is within 60 nm either side of the trough between 27W-30W. Scattered moderate to isolated strong convection is within 180 nm north of the ITCZ between 50W-54W and within 60 nm of the ITCZ between 41W-44W. Scattered moderate convection is within 60 nm north of the trough between 35W-37W, and within 60 nm north of the trough between 39W-41W. ...GULF OF MEXICO... High pressure stretches south-southwestward from the eastern United States to the the NE and north-central Gulf areas. A trough extends from just northwest of the northern Yucatan Peninsula south to near 19N91W. Scattered showers and thunderstorms are just inland eastern Texas and southwestern Louisiana. Elsewhere, mainly dry conditions prevail. The gradient presently in place supports moderate to fresh northeast to east winds and seas of 4-6 ft across the majority of the Gulf. For the forecast, high pressure will dominate the Gulf waters supporting moderate to fresh easterly winds over just about the entire basin. As the gradient slackens today, this will allow for these winds to diminish to gentle to moderate speeds. Light to gentle winds are forecast elsewhere through Fri night. A pretty robust cold front for the early autumn season is expected to move across the northern Gulf Fri into Sat followed by fresh to strong winds and moderate seas. ...CARIBBEAN SEA... A broad mid to upper-level trough reaches from off the South Carolina coast southward through central Cuba to off the coast of Nicaragua. Divergent flow aloft is supporting scattered showers and thunderstorms off the coast of southeast Cuba. Isolated thunderstorms prevail across the remainder of the basin east of 81W, with somewhat drier conditions over the northwest part of the basin. East of 68W, winds are from the southeast and of moderate speeds along with seas of 3-5 ft. In the Yucatan Channel, winds are of moderate speeds from the northeast with seas of 4-6 ft. Elsewhere, winds are mainly light to gentle with seas 1-3 ft. Satellite imagery shows scattered showers and thunderstorms tied to outer rainbands from Philippe continue over the northeast and far eastern sections of the Caribbean. An area of increasing scattered moderate convection is evident south of the Dominican Republic and between 68W-71W. Moderate to fresh trade winds are confined to the eastern part of the sea, while light to gentle trade winds are over the rest of the sea, except for moderate trade winds in the far northwest part of the seas. Seas are generally 4-6 ft. For the forecast, Tropical Storm Philippe is near 24.8N 65.9W at 5 AM EDT, and is moving north at 12 kt. Maximum sustained winds are 35 kt with gusts to 45 kt, and the minimum central pressure is 1004 mb. Philippe will move to near 26.7N 66.0W this afternoon and continue northward through Sat well away from the forecast waters. Scattered showers and thunderstorms from trailing outer rainbands are impacting the northeast part of the Caribbean. This activity is expected to pull away from the forecast waters during today. Light to gentle trade winds will be over the basin through the next few days, except for moderate to locally fresh southerly winds in the eastern Caribbean today. A tropical wave currently moving across the waters east of the Lesser Antilles near 58W will move into the eastern Caribbean today and move across the rest of the Caribbean during the upcoming weekend. Scattered showers and thunderstorms are expected to trail this wave. ...ATLANTIC OCEAN... Please refer to the Special Features section for details on Tropical Storm Philippe. In addition, please refer to the Tropical Waves and Monsoon Trough/ITCZ for convection in the tropical Atlantic. An upper-level trough extending from South Carolina southward to the western Caribbean is helping to sustain scattered showers and thunderstorms north of Hispaniola and north of 25.5N between 73W-79W. Scattered moderate convection is also noted from 27N to 31N between 60W and 68.5W. Fresh E winds and 6-8 ft seas are over the western Atlantic north and northeast of the Bahamas, outside of Philippe. A 1018 mb high pressure is centered near 24N51W, with a surface ridge extending from 30N30W to the high pressure to 26N58W. To the north of the high, scattered moderate convection is noted within a line that extends from 31N36W to 28N45W. Moderate to fresh southwest to west winds and 6-8 ft seas are also found to the north of that surface ridge. Areas of rain with embedded showers are over the northeast Atlantic from 21N to 29N between 21W-25W mainly associated to a sharp upper-level trough that extends from near 31N22W to 26N24W and to 17N27W. A surface trough extends from inland Africa near 19N15W northwest to 26N20W. No significant convection is occurring with this trough. In the tropical latitudes, moderate to fresh trades and 6-8 ft seas prevail from 10N-22N between 38W-61W. For the forecast, Tropical Storm Philippe is near 24.8N 65.9W at 5 AM EDT, and is moving north at 12 kt. Maximum sustained winds are 35 kt with gusts to 45 kt, and the minimum central pressure is 1004 mb. Philippe will move to near 26.7N 66.0W this afternoon, then strengthen slightly as it moves to near 30.0N 66.0W late tonight with maximum sustained winds 40 kt gusts 50 kt. Philippe is forecast to lift north of the area to near 33.3N 66.0W Fri afternoon and continue well north of the area through Sat as it transitions to an extratropical cyclone. Fresh northeast winds north of the Bahamas will diminish today. $$ Aguirre