000 AXNT20 KNHC 212310 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Sun Oct 22 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 2300 UTC. ...SPECIAL FEATURES... Hurricane Tammy is centered near 17.0N 61.3W at 21/2100 UTC or 40 nm N of Guadeloupe, moving NNW at 9 kt. Estimated minimum central pressure is 988 mb. Maximum sustained wind speed is 75 kt with gusts to 90 kt. Peak seas are around 29 ft. Numerous moderate to isolated strong convection is noted from 13N to 19N between 59W and 66W. Tammy will continue moving NNW through Sunday, followed by a turn toward the north on Monday. On the forecast track, the center of Tammy will move near or over portions of the Leeward Islands through early Sunday, and then move north of the northern Leeward Islands by Sunday afternoon. Slow strengthening is possible during the next few days. Swells generated by Tammy will continue to affect portions of the Lesser Antilles during the next few days. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office and 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 Tammy NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. East Atlantic Storm Warning: Meteo-France has issued a STORM WARNING for the Irving and Madeira Offshore Zones. Please see the latest High Seas Warning and High Seas Forecast issued by Meteo- France at https://wwmiws.wmo.int/index.php/affiche/2 for more information. ...MONSOON TROUGH/ITCZ... The monsoon trough exits the coastal plains of Senegal near 13N16W to 12N19W. The ITCZ extends from 12N19W to 08N34W. Scattered moderate to isolated strong convection is noted from 03N to 10N between 20W and 39W. GULF OF MEXICO... A cold front extends from just north of Tampa Bay, Florida, to 28N86W. A stationary front continues from 28N86W to Galveston, Texas. Surface observations show gentle to moderate NE winds north of the front with seas to 3 ft. 1016 mb high pressure is centered near 24N91W. Light to gentle anticyclonic flow prevails over the remainder of the Gulf of Mexico, with 1-3 ft seas. For the forecast, the cold front will move southward tonight while weakening. Another cold front will move through the NE Gulf late Sun through Mon. High pressure building in the wake of the front will support moderate to fresh E to SE winds and building seas Sun night through the middle of next week. Winds will further increase to fresh to strong speeds across most of the Gulf waters by Tue night into Wed as high pressure strengthens. CARIBBEAN SEA... Please see SPECIAL FEATURES section above for information on HURRICANE TAMMY. Seas of 8-12 ft are noted in some Atlantic passages between the Northern Leeward Islands, in the vicinity of Hurricane Tammy. Light to gentle trades prevail in the eastern and central Caribbean with 4-6 ft seas. In the western Caribbean, a trough extends from eastern Cuba to the Nicaragua coastline near 15N82W. Scattered thunderstorms are noted within 70 nm of the trough. Gentle to locally moderate N winds prevail in this area with seas of 1-3 ft. Scattered moderate convection is noted in the southwest Caribbean, from 09N to 15N between 76W and 83W. For the forecast, Hurricane Tammy is near 17.0N 61.3W at 5 PM EDT, and is moving north-northwest at 9 kt. Maximum sustained winds are 75 kt with gusts to 90 kt, and the minimum central pressure is 988 mb. Tammy will move to 18.1N 62.1W Sun morning, 19.5N 62.9W Sun afternoon, 20.9N 63.5W Mon morning, 22.2N 63.7W Mon afternoon, 23.1N 63.6W Tue morning, and 23.8N 63.4W Tue afternoon. Tammy will change little in intensity as it moves to near 25.7N 62.7W Wed afternoon. A broad area of low pressure located over the southwestern Caribbean Sea continues to produce disorganized showers and thunderstorms. Some slow development of this system is possible before it moves inland over Central America by late Monday. A weak cold front will move into the northwest Caribbean by late Mon. ATLANTIC OCEAN... Please see the SPECIAL FEATURES section for information on HURRICANE TAMMY and an EAST ATLANTIC STORM WARNING issued by Meteo-France. A cold front extends from 31N71W to Cape Canaveral, Florida. Fresh to locally strong WNW winds are north of the front. A surface trough is from 31N66W to eastern Cuba. Scattered showers are along the surface trough. In the vicinity of these two features, 8-12 ft seas are north of a line from 31N60W to 28N75W to 31N77W. In the central tropical Atlantic, as surface trough extends from 14N44W to 04N50W. Scattered moderate isolated strong convection is from 07N to 15N between 39W and 53W. Earlier scatterometer data showed fresh to strong E winds near this surface trough with seas of 6-8 ft. In the northeastern tropical Atlantic, a cold front extends from 31N16W to 27N27W to 30N41W. Fresh to strong NW winds are north of the cold front with 8-12 ft seas. Elsewhere in the Atlantic, E winds are moderate with 4-7 ft seas in open waters. For the forecast W of 55W, Hurricane Tammy is near 17.0N 61.3W at 5 PM EDT, and is moving north-northwest at 9 kt. Maximum sustained winds are 75 kt with gusts to 90 kt, and the minimum central pressure is 988 mb. Tammy will move to 18.1N 62.1W Sun morning, 19.5N 62.9W Sun afternoon, 20.9N 63.5W Mon morning, 22.2N 63.7W Mon afternoon, 23.1N 63.6W Tue morning, and 23.8N 63.4W Tue afternoon. Tammy will change little in intensity as it moves to near 25.7N 62.7W Wed afternoon. Farther W, a cold front extends from 31N70W to northern Florida. This front will weaken and stall E of Bermuda through eastern Cuba by late Sun. At the same time, a second cold front will move off the northeast Florida coast, reaching from Bermuda to Fort Lauderdale, Florida, on Mon. Looking ahead, high pressure building in the wake of the front combined with tropical cyclone Tammy will bring an increase in winds and seas across the forecast area likely Tue through Wed. $$ AReinhart