000 AXNT20 KNHC 281801 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Thu Sep 28 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 1200 UTC surface analysis and satellite imagery through 1745 UTC. ...SPECIAL FEATURES... Tropical Storm Philippe is centered near 18.6N 54.6W at 28/1500 UTC or 490 nm E of the Northern Leeward Islands, moving WNW at 2 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Peak seas near and just southwest of the center are around 21 ft. Seas of 12 ft or greater extend outward up to 300 nm from the center in the N semicircle, 180 nm SE quadrant and 120 nm SW quadrant. Scattered moderate to strong convection is within 200 nm SE semicircle and 190 nm NW quadrant. A slow westward or southwestward motion is expected during the next few days with a little change in strength. 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 Philippe NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Gale Warning Associated with Invest Area (AL91) was upgraded at 15Z to Tropical Storm Rina. The newly formed Tropical Storm Rina is centered near 17.4N 45.0W at 28/1500 UTC or 1030 nm E of the Northern Leeward Islands, moving NNW at 9 kt. Estimated minimum central pressure is 1005 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Peak seas near and just northwest of the center are around 14 ft. Seas of 12 ft or greater extend outward 120 nm in the east semicircle. Scattered moderate to strong convection is within 115 nm in the eastern semicircle and 60 nm in the southeast semicircle. Rina is expected to turn more westward later today or tomorrow, while some gradual strengthening is forecast during the next few days. 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 Philippe NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...TROPICAL WAVES... A new tropical wave has been introduced in the 12Z surface analysis off the coast of west Africa and is centered near 19W south of 19N. Scattered strong convection is depicted from 05N to 16N between 13W and 21W. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic near 18N16W and extends southward to 10N23W and end at 08N27W. Isolated moderate to strong convection is noted from 08.5N to 11N between 27W and 29W. ...GULF OF MEXICO... A stationary front extends westward from north of Tampa, Florida area to just south of New Orleans, Louisiana. Scattered moderate convection is seen near and up to 80 nm along both sides of this front. A surface trough is analyzed from near Marco Island, Florida to near 23N88W. Isolated to scattered thunderstorms are along both sides of this trough axis. Another broad surface trough extends from the NW Gulf near 28N91W southward to the east- central Bay of Campeche. Isolated thunderstorms are located within 70 nm of the coast of southern Texas. Fresh NE to E winds and 4-5 ft seas are likely occurring to the north of the aforementioned stationary front. Elsewhere, gentle winds and 1-3 ft seas prevail. For the forecast, the aforementioned stationary front is draped across the northern Gulf of Mexico. By Sunday, this front should move southward as a cold front. To the north of the front, fresh E winds are expected over the northern Gulf through the forecast period due to strong high pressure ridging over the southeastern United States. ...CARIBBEAN SEA... Total precipitable water imagery shows very moist air over the northwest Caribbean. A mid-level trough is located over western Cuba, where scattered moderate convection is occurring. Scattered thunderstorms are also noted in the Yucatan Channel and in the Gulf of Honduras. Isolated showers and thunderstorms are depicted over the SW Caribbean in association to the East Pacific monsoon trough. A deep layer trough over the central Caribbean is producing scattered showers and thunderstorms in the area. Moderate trades prevail over much of the basin, except for gentle over the far western Caribbean and over the far E portion of the basin. Seas range from 2-5 ft across the basin. For the forecast, Tropical Storm Philippe is near 18.6N 54.6W at 11 AM EDT, and is moving west-northwest at 2 kt. Maximum sustained winds are 45 kt with gusts to 55 kt, and the minimum central pressure is 1002 mb. Philippe will move to 18.7N 55.1W this evening, 18.6N 55.6W Fri morning, 18.4N 56.1W Fri evening, 18.0N 56.7W Sat morning, 17.6N 57.2W Sat evening, and 17.3N 57.5W Sun morning. Philippe will change little in intensity as it moves to near 17.7N 58.2W early Mon. Rough seas across the forecast zones east of the Leeward Islands generated by Tropical Storm Philippe will start to subside toward the end of the week south of 17N, but will continue 8 to 12 ft north of 17N into the weekend. Mainly moderate trade winds will prevail across the central Caribbean, with gentle to moderate winds elsewhere through the weekend. ...ATLANTIC OCEAN... Refer to the Special Features section above on Tropical Storm Philippe and Rina. A stationary front extends west-southwestward from 31N77W to Port Canaveral, Florida. Fresh to strong NE winds and 8-9 ft seas prevail north of 30N and west of 79W. Scattered showers and isolated thunderstorms are located west of a line from 31N77W to 29N80W. Elsewhere west of 65W, winds are moderate or weaker with 5-9 ft seas in mixed swell. Farther east, the subtropical surface ridge extends east-west along 28/29N between 30W and 56W, anchored by a 1024 mb high pressure centered near 32N25W. From 26N to 31N between 30W and 60W, winds are light to moderate with 6-8 ft seas in mixed swell. Winds of 20 to 45 kt and seas of 9-21 ft associated with Tropical Storm Philippe and newly formed Tropical Storm Rina cover the area from 14N to 25.5N between 40W and 62W. Fresh to locally strong NE winds and 7-9 ft seas prevail north of the Cabo Verde Islands to 25N between the coast of Africa and 35.5W. For the forecast west of 55W, Tropical Storm Philippe is near 18.6N 54.6W at 11 AM EDT, and is moving west-northwest at 2 kt. Maximum sustained winds are 45 kt with gusts to 55 kt, and the minimum central pressure is 1002 mb. Philippe will move to 18.7N 55.1W this evening, 18.6N 55.6W Fri morning, 18.4N 56.1W Fri evening, 18.0N 56.7W Sat morning, 17.6N 57.2W Sat evening, and 17.3N 57.5W Sun morning. Philippe will change little in intensity as it moves to near 17.7N 58.2W early Mon. Rough seas ahead of the storm are east of 62W, and will continue to spread east of 68W through the end of the week. Tropical Storm Rina is near 17.4N 45.0W at 11 AM EDT, and is moving north-northwest at 9 kt. Maximum sustained winds are 35 kt with gusts to 45 kt, and the minimum central pressure is 1005 mb. Rina will move to 18.5N 45.8W this evening, 19.2N 46.8W Fri morning, 19.6N 47.8W Fri evening, 19.9N 49.0W Sat morning, 20.4N 50.4W Sat evening, and 21.1N 52.2W Sun morning. Rina will change little in intensity as it moves to the early Mon. Elsewhere, fresh to strong NE winds and seas 8 to 9 ft will prevail through this evening north of the Bahamas and east of Florida in NE swell. $$ KRV