000 AXNT20 KNHC 062116 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Wed Oct 6 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 a tropical wave is near 26W, from 16N southward, moving W at 15 to 20 kt. Scattered moderate convection is found from 01N to 05N between 25W and 30W. The axis of a tropical wave is near 51W, from 18N southward, moving W at 15 to 20 kt. Scattered moderate and isolated strong convection is noted from 07N to 16N between 50W and 55W. The axis of a tropical wave is near 83W, from 17N southward, moving W at 5-10 kt. Scattered moderate to strong convection covers the area from 08N to 20N between 80W and 86W. Periods of heavy rainfall are possible over portions of Nicaragua and Costa Rica through Thursday night. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal plains of Guinea-Bissau near 12N16W to 09N17W. The ITCZ extends from 09N17W to 04.5N25W. It resumes from 05N28W to 08N50W, then again from 07.5N54W to 07.5N59W. Aside from the convection mentioned above, scattered moderate isolated strong convection is noted from 03N to 07N between 16W and 25W, and within 150 nm if the ITCZ between 30W and 50W. GULF OF MEXICO... A stationary front extends from Mobile, Alabama to near Veracruz Mexico. Scattered moderate and isolated strong convection is noted within 270 nm east of the front and north of 24N. Scattered moderate showers are also near the front over the western Bay of Campeche south of 20N. High pressure of 1018 mb is centered west of the front along the coast of Texas. Gentle to moderate winds are noted west of the front, reaching fresh to locally strong over the far SW Gulf. Light to gentle winds prevail east of the front. Seas are in the 3-4 ft range over the far SW Gulf and 1-3 ft elsewhere. For the forecast, the stationary front will meander through Thu before dissipating. Weak high pressure to the NW will support moderate to locally fresh northerly winds over Veracruz adjacent waters through Thu. High pressure will build modestly across the basin during the weekend and continue through early next week. CARIBBEAN SEA... Strong convection over the western Caribbean Sea is described above in the tropical waves section. A high pressure ridge extends from 1024 mb high pressure near 34N62W SW to the central Bahamas. The pressure gradient between the area of high pressure and lower pressure across Colombia is supporting fresh to strong winds over the central Caribbean. Moderate to fresh winds prevail over the eastern Caribbean with gentle to moderate winds over the western Caribbean. Seas are in the 7-10 ft range in the central Caribbean, 3-6 ft over the eastern Caribbean, and 1-3 ft over the western Caribbean. For the forecast, high pressure north of the area will continue to support fresh trade winds across the eastern, central and southwest basin with locally strong winds along Hispaniola adjacent waters and the south-central Caribbean. These winds and seas to 8 ft will diminish Thu early in the evening as the ridge slides ENE and a weaker pressure gradient establishes across the area. Moderate to locally fresh trades will dominate these regions Thu night through Sat, diminishing to mainly moderate across the E half of the basin Sun through Mon night. Otherwise, a tropical wave will reach the tropical Atlantic waters tonight and support moderate to fresh winds and building seas through early in the weekend. ATLANTIC OCEAN... A surface trough off the southeast U.S. coast extending from 33N73W to 26N79W is moving slowly NW. Recent buoy and ASCAT wind data indicate that a weak area of low pressure is developing along the trough about 150 nm east of the northeastern coast of Florida. Disorganized scattered moderate showers and isolated tstorms are noted from 28N-31N between 70W-79W. Upper-level winds are forecast to remain unfavorable for tropical cyclone development while the low moves slowly northward and then northeastward off the southeastern United States coast during the next few days. The system has a low chance of formation during the next 48 hours. A 1026 mb high pressure is centered just east of Bermuda. The gradient between this high pressure and 1009 mb low pressure along the coast of NW Colombia is producing fresh E winds across the southeast Bahamas and north of Hispaniola, where seas are 7 to 9 ft. Gentle to moderate winds cover the area north of 25N between 60W and Florida, where seas are 4 to 6 ft. Fresh to locally strong trade winds will continue south of 25N through Thu. Moderate to locally fresh winds will then gradually diminish to gentle to moderate Fri and continue through the weekend. Northerly swell generated from Sam east of 72W will diminish through tonight. Farther east, a surface trough associated with the remnants of Victor is producing scattered moderate and isolated strong convection from 23N-27N between 49W-56W. ASCAT data show fresh NE to E winds within the area of convection. East of 40W, broad surface ridging prevails. ASCAT shows fresh trade winds across the tropical Atlantic from 10N-20N, where seas are 6 to 7 ft. Saharan air is dominating the zone north of 13N between 25W and the tropical wave along 50W. The Cumbre Vieja volcano, located on the island of La Palma in the Canary Islands, has been erupting almost continuously since 19 September. Marine and aviation interests should monitor this ongoing situation by reading the Volcanic Ash Advisory issued by Meteo-France at http://vaac.meteo.fr/volcanoes/la-palma/ $$ AL