000 AXNT20 KNHC 102204 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Mon Oct 11 2021 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 2200 UTC. ...TROPICAL WAVES... The axis of an active tropical wave is near 51W south of 16N, moving W at 10-15 kt. Scattered moderate to isolated strong convection is from 07N to 13N between 50W and 55W. Environmental conditions are forecast to be marginally conducive for some additional development of this system while it moves west- northwestward at about 15 mph over the next few days. The disturbance is expected to approach the central and northern Lesser Antilles by late Monday and early Tuesday, and interests in these areas should monitor the progress of this system. Regardless of development, the system will produce locally heavy rainfall and gusty winds across portions of the central and northern Lesser Antilles on Tuesday, and across the Virgin Islands and northern Lesser Antilles on Wednesday. The axis of a tropical wave is near 65W south of 19N, moving W at 10-15 kt. Scattered moderate isolated strong convection is from 13N to 18N between 57W and 65W. The axis of a tropical wave is near 80W, moving W at 10-15 kt. Scattered moderate convection is noted over the SW Caribbean, S of 13N. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of W Africa near 08N13W to 09N20W. The ITCZ continues from 09N20W to 06N35W to 08N48W. Scattered moderate convection is from 05N to 08N between 30W and 42W. Scattered moderate isolated strong convection is from 07N to 15N between 42W and 50W. ...GULF OF MEXICO... High pressure prevails across the Gulf waters. Moderate to fresh winds are over the far NW Gulf, with gentle to moderate winds elsewhere W of 90W. East of 90W, light to gentle winds prevail. Seas are in the 3-5 ft range over the far NW Gulf, and 1-3 ft elsewhere. For the forecast, high pressure will prevails across the Gulf. Moderate to fresh southerly winds will prevail into mid week over the western Gulf between the ridge and lower pressure over the Southern Plains and northern Mexico. Gentle to moderate breezes will persist elsewhere through Fri. ...CARIBBEAN SEA... Fresh to strong winds are noted over the far NE Caribbean with a locally tight pressure gradient between a tropical wave in the eastern Caribbean, and high pressure NE of the Caribbean. Moderate to fresh winds are over the central Caribbean. Light to gentle winds prevail elsewhere. Seas are in the 6-7 ft range over the far NE Caribbean and 3-5 ft elsewhere over the eastern and central Caribbean. Over the western Caribbean, seas are in the 1-3 ft range. For the forecast, fresh to strong winds and a few thunderstorms persist over the northeast Caribbean, associated with tropical wave move through the eastern Caribbean and an upper trough north of Puerto Rico. Winds and seas will diminish near the wave as it moves into the central Caribbean through mid week, and into the western Caribbean Thu and Fri. Another tropical wave currently currently passing 50W will enter the eastern Caribbean Tue and the central Caribbean Thu and Fri. Expect rough seas in Atlantic waters east of the Leeward Islands into mid week behind the tropical wave as northerly swell reaches the area. Mostly gentle to moderate winds and slight to moderate seas will persist elsewhere. ...ATLANTIC OCEAN... A trough extends from low pressure off the Carolinas to the eastern Straits of Florida. Scattered moderate and isolated strong convection are noted within 450 nm east of the trough. A second trough extends from 30N34W to 25N49W. Scattered moderate convection is noted in the vicinity of the trough. A cold front has entered the far northern portion of the discussion area extending from 31N41W to 29N48W to 31N57W. Moderate to fresh winds are noted south of 22N between 40W and 70W, while light to gentle winds prevail elsewhere. Seas are in the 8 to 10 ft range south of 21N, and 3-5 ft over the open waters north of 21N. West of the Bahamas, seas are in the 1-3 ft range. The Cumbre Vieja volcano, that is on the island of La Palma in the Canary Islands, has been erupting since 19 September 2021. Currently, volcanic ash is seen over the vicinity of the volcano. Marine and aviation interests should monitor this on-going situation, by reading the Volcanic Ash Advisory, that is issued by Meteo-France, at http://vaac.meteo.fr/volcanoes/la-palma/. For the forecast W of 65W, a trough reaches from low pressure off the Carolinas to the eastern Straits of Florida. Scattered thunderstorms are active mainly west of 70W, ahead of the trough. The trough and associated weather will move little through Mon, then drift east and weaken through mid week. Farther south, a tropical wave moving through the eastern Caribbean will bring fresh to strong winds and occasionally rough seas south of 22N through late Mon, then will diminish. Elsewhere, generally moderate winds and seas will persist through Fri. $$ AL