000 AXNT20 KNHC 182321 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Tue Oct 19 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 2100 UTC. ...TROPICAL WAVES... The axis of a tropical wave is near 27W from 01N to 14N, moving westward at 10-15 kt. Scattered moderate convection is from 04N to 07N between 26W and 28W. The axis of a tropical wave is near 45W/46W from 02N to 16N, moving westward at 10-15 kt. Scattered moderate to isolated strong convection is from 07N to 10N between 43W-48W. The axis of a tropical wave is near 60W south of 16N, moving westward at 10-15 kt. No significant convection is noted at this time with this wave. The axis of a tropical wave is near 82W south of 17N, moving westward at 10-15 kt. Scattered moderate convection is noted from 13N to 15N between 81W and 83W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends off the coast of Senegal near 17N16W to 07N24W. The ITCZ continues from 06N30W to 06N43W, then resumes near 06N47W to 05N53W. In addition to the convection mentioned above in the Tropical Waves section above, scattered moderate convection is observed within 60 nm north of the ITCZ between 30W and 40W. GULF OF MEXICO... A stationary front reaches from the Straits of Florida to 22N90W to 18.5N93W. Latest scatterometer data showed fresh E winds in the Straits of Florida north of the front, and moderate to fresh N winds over the southwest Gulf, although this is diminishing rapidly. Seas are 5 to 7 ft in the southwest Gulf with residual N swell, 4 to 6 ft in the Straits of Florida, and 3 to 5 ft elsewhere. For the forecast, the front will dissipate through Wed. Winds and seas will subside quickly off of Veracruz, Mexico through midnight. Winds across the Gulf will gradually veer to the east Tue as high pressure to the north slides eastward. Weak high pressure will dominate the Gulf for the remainder of the week. CARIBBEAN SEA... Refer to the section above for details on the tropical waves moving across the basin. A weak pressure pattern prevails across the Caribbean waters. Moderate to fresh E winds are noted off Venezuela, and along the ABC islands. Light to gentle winds and seas of 1-3 ft prevail elsewhere across much of the Caribbean waters. For the forecast, the weak pressure gradient and tranquil marine conditions will persist across the Caribbean basin through tonight. A cold front across the NW Atlc will move SE through Wed before stalling from near 25N65W to the Straits of Florida. High pressure building N of the front will bring a return to moderate trade winds to the Caribbean early Tue and then become moderate to fresh winds Wed through Sat. ATLANTIC OCEAN... Refer to the section above for details on the tropical waves moving across the basin. A cold front extends across the Atlantic waters from near 31N62W to the central Bahamas where it becomes a stationary front into the Straits of Florida. Moderate to fresh northerly winds are noted behind the front, with 6 to 8 ft seas. Moderate to fresh SW winds with 4 to 5 ft are noted east of the front to 50W, north of 28N. Gentle winds persist elsewhere west of 50W, with 3 to 5 ft seas. Farther east, another front reaches from 31N27W to 27N32W then is stationary to 25N43W after which a trough extends to near 20N50W. A radar altimeter satellite pass showed evidence of seas to 8 ft following this front east of 30W, likely in NW swell. Weak high pressure dominates elsewhere supporting moderate to fresh trades south of 20N with 4 to 6 ft seas, and gentle to moderate winds north of 20N with 5 to 7 ft seas in NW swell. The Cumbre Vieja volcano, on the island of La Palma in the Canary Islands, has been erupting since 19 September 2021. Light to moderate volcanic ash is expected in the area east of the volcano, while high ash concentrations are close to the volcano. 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/. For the forecast west of 65W, the cold front over the western Atlantic will continue moving slowly southeastward before becoming stationary from near 25N65W to the Straits of Florida, then dissipating Thu night. High pres will shift ESE across the western Atlc along 31N-32N through Thu, producing strong winds immediately north of the front. $$ Christensen