000 AXNT20 KNHC 312108 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Thu Sep 1 2022 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 2000 UTC. ...SPECIAL FEATURES... Central Tropical Atlantic: Data from a NOAA aircraft reconnaissance mission earlier today showed little change in organization of the 1008 mb area of low pressure located several hundred nautical miles east of the Lesser Antilles, near 15.5N51W. Numerous moderate and isolated strong convection is noted from 13N to 19N between 47W and 53W, with scattered moderate and isolated strong convection elsewhere from 07N to 20N between 45W and 58W. Currently, winds are 20-25 kt with seas of 8-10 ft, mainly in the northern semicircle. Although environmental conditions are only marginally conducive, additional gradual development of this system is expected and a tropical depression is likely to form within the next couple of days. The disturbance is forecast to move slowly west- northwestward, toward the adjacent waters of the northern Leeward Islands. This feature has a medium chance of tropical cyclone formation through 48 hours, and a high chance over the next 5 days. Please read the latest Tropical Weather Outlook issued by the National Hurricane Center at www.hurricanes.gov and the latest High Seas Forecast issued by the National Hurricane Center at https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for additional information. Eastern Tropical Atlantic: Showers and thunderstorms associated with a broad 1006 mb area of low pressure located just to the northeast of the Cabo Verde Islands near 17.5N21W have changed little since earlier today. Scattered moderate convection is noted from 15.5N to 20N between 19W and 27W. This low is along a tropical wave which extends south of 21N along 21W. Some gradual development is possible, and the system could become a short- lived tropical depression over the far eastern Atlantic during the next couple of days. By late this week, environmental conditions are forecast to become increasingly unfavorable for further development. Regardless, the system could bring locally heavy rainfall to portions of the Cabo Verde Islands through Thu. This feature has a medium chance of tropical cyclone formation through 48 hours, and a medium chance over the next 5 days. Please read the latest Tropical Weather Outlook issued by the National Hurricane Center at www.hurricanes.gov and the latest High Seas Forecast issued by Meteo-France at http://weather.gmdss.org/II.html for additional information. Central Subtropical Atlantic: A 1016 mb area of low pressure is showing signs of organization over the central subtropical Atlantic about 850 nautical miles west-southwest of the westernmost Azores, near 38N46W. Scattered moderate convection is noted within 120 nm southeast of a line from 39.5N43W to the low to 34.5N50W. Environmental conditions are expected to be conducive for development, and a tropical or subtropical depression is likely to form within the next day or so, while the system drifts generally eastward. This feature has a high chance of tropical cyclone formation during the next 48 hours. Please read the latest Tropical Weather Outlook issued by the National Hurricane Center at www.hurricanes.gov and the latest High Seas Forecast issued by the Ocean Prediction Center at https://www.ocean.weather.gov/shtml/NFDHSFAT1.php for additional information. ...TROPICAL WAVES... A NW Caribbean Sea tropical wave has its axis near 85W, south of 21N, drifting very slowly at 5 kt or less. Scattered moderate and isolated strong convection is located from 13N to 18N between 80W and 85W, including over portions of extreme eastern Honduras and NE Nicaragua, with similar activity from 16N to 18N between 85W and 87W just northeast of the Gulf of Honduras. A SW Gulf of Mexico tropical wave has its axis near 93W/94W, south of 20N, across southern Mexico just east of the Chivela Pass, and into the eastern Pacific Ocean, drifting slowly around 5 kt. Nearby convection is confined to land. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near the border of Western Sahara and Mauritania from 21.5N17W to 1006 mb low pressure near 17.5N21W to 11N33W to 1008 mb low pressure near 15.5N51W to just off the coast of Guayana at 08N59W. Outside of tropical wave activity, widely scattered moderate convection is observed from 06N to 12N between 20W and 38W. GULF OF MEXICO... A surface trough stretches from the Florida panhandle near Apalachee Bay to the central Gulf near 24N89W. Scattered showers and isolated thunderstorms are occurring near this feature. A few widely isolated showers and thunderstorms are also observed throughout the basin. Otherwise, a relaxed pressure gradient is supporting favorable marine conditions with gentle winds and slight seas across the Gulf. For the forecast, E winds should pulse to moderate or fresh Fri and Sat nights over the SW Gulf due to a diurnal trough moving off of the Yucatan. Elsewhere, high pressure will dominate the weather pattern across the Gulf waters through the early next week maintaining gentle to moderate winds and slight seas. CARIBBEAN SEA... The pressure gradient between the Bermuda high north of the basin and 1009 mb low pressure along the coast of Colombia near 10.5N76W is supporting moderate to fresh trades in the central Caribbean from 11N to 18N. Gentle to moderate trades prevail elsewhere, except light to gentle in the SW Caribbean and between Haiti and eastern Cuba. Seas are 4-6 ft in the central Caribbean, and mainly 3-4 ft elsewhere, except 2-3 ft in the far SW Caribbean. Convection in the western Caribbean is described in the tropical wave sections. Thunderstorms are occurring just offshore and along the coast of Colombia within 150 nm northeast of the low. For the forecast, the Bermuda High north of the Caribbean Sea will continue to support moderate to fresh E trades across the S central Caribbean through Fri. SE winds over the Gulf of Honduras will reach moderate to fresh Thu through Fri night. Elsewhere, winds and seas will be quiescent. ATLANTIC OCEAN... Please see the Special Features section above for more information on areas of low pressure near 17.5N21W and 15.5N51W with the potential to develop into tropical cyclones. Elsewhere a 1018 mb high pressure centered near 28N68W is dominating the pattern, creating light to gentle anticyclonic winds and 2-4 ft seas in the western tropical Atlantic. A weak stationary front along the SE US coast from near Cape Fear, North Carolina to the South Carolina Low Country is generating scattered moderate convection north of 30N between 75W and 79W. In the eastern Atlantic, a tighter pressure gradient is generating moderate to fresh NE winds, locally strong near the Canary Islands, and 5-7 ft seas. Fresh to locally strong SW winds and seas of 7-8 ft are noted south of the monsoon trough between the coast of Africa and 25W. For the forecast west of 55W, the area of low pressure currently near 15.5N51W is forecast to move slowly toward the west- northwest, reaching the far SE forecast waters west of 55W on Thu. Elsewhere, gentle to moderate winds will prevail across much of the area through early next week. $$ Lewitsky