000 AXNT20 KNHC 190542 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 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 0000 UTC surface analysis and satellite imagery through 0530 UTC. ...TROPICAL WAVES... A far eastern Atlantic tropical wave has its axis along 29N from 02N to 16N, moving westward at 10-15 kt. Scattered moderate to isolated strong convection is within 120 nm east of the wave axis from 05N to 07N. A central Atlantic tropical wave has its axis along 48W from 02N to to 17N, moving westward at 10-15 kt. Latest and recent satellite imagery depicts the cloud pattern of this wave quite noticeably. The imagery shows scattered moderate convection within 120 nm east of the axis from 08N to 10N. A recent ASCAT pass revealed a northeast to east-southeast shift of gentle winds across the wave axis. Another central Atlantic tropical has its axis from 20N58W to 14N59W and south to inland Guyana. It is moving westward at 10-15 kt. This wave is underneath an elongated northeast to southwest upper-level trough that is aiding the scattered moderate convection occurring within 120 nm east of the wave axis from 12N to 20N. A recent ASCAT pass revealed a gradual northeast to east-southeast shift of gentle winds across the wave axis. A western Caribbean Sea tropical wave has its axis near 83W south of 16N. It is moving westward at about 10 kt. Scattered moderate to isolated strong is near the northern part of the wave from 14N to 16N between 81W-84W. Similar convection is just to the northwest of the wave from 16N to 18N between 83W-85W. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends off the coast of Senegal near 16N17W and continues to 07N24W. The ITCZ continues from 07N24W to 06N28W. It then resumes near 06N30W to 06N39W to 07N46W and continues to the west of a tropical wave from 07N49W to 05N53W. In addition to the convection mentioned above in the Tropical Waves section above, scattered moderate to isolated strong convection is within 60 nm north of the ITCZ between 29W-40W, and within 30 nm south of the ITCZ between 40W-45W. Scattered moderate convection is within 30 nm north of the ITCZ between 24W-27W. GULF OF MEXICO... A stationary front extends from the Straits of Florida to 22N90W and to 18.5N93W. Recent ASCAT data shows gentle to moderate east winds north of the front, except for fresh northeast to east winds over the Straits of Florida and gentle to moderate north winds over the southwest Gulf. Seas are 4-6 ft in the southwest Gulf and in the Straits of Florida, and 3 to 5 ft elsewhere except for slightly lower seas of 2-4 ft in the west-central Gulf area. For the forecast, the front will slowly dissipate through Wed. Winds across the Gulf will gradually veer to the E Tue as high pressure to the N slides eastward. Weak high pres 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 east winds are noted off Venezuela, and along the ABC islands per recent ASCAT data passes. Seas of 2-4 ft are over these waters. Light to gentle winds and seas of 1-3 ft continue elsewhere across much of the Caribbean waters, except for higher seas of 3-5 ft over the northwestern Caribbean. For the forecast, the weak pressure gradient and tranquil marine conditions will persist across the Caribbean basin through this morning. A cold front across the NW Atlantic will move southeastward through Wed before stalling from near 25N65W to the Straits of Florida. High pressure building north 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 31N61W to the central Bahamas where it becomes a stationary front to across the Straits of Florida. Recent ASCAT data passes indicate moderate to fresh north to northeast winds within 90 to 120 nm north of the front and mainly gentle northeast to east winds elsewhere north of the front. Seas are in the range of 6-8 ft due to a northwest swell. Moderate to fresh southwest winds along with seas of 4-5 ft are east of the front to 50W and north of 28N. Gentle winds persist elsewhere west of 50W along with 3-5 ft seas due to a north to northeast swell. Farther east, another cold front reaches from near 31N27W to 27N32W, where it becomes a weakening stationary front to 26N43W and a trough from there to 22N50W and to near 20N50W. Northwest swell producing seas peaking at 8 ft is following in behind this front north of 31N. This swell set if forecast to move through the waters north of 30N and between 35W-41W later this morning. Weak high pressure dominates elsewhere supporting gentle to moderate trades south of 20N along with 4-6 ft seas, with the exception of moderate to fresh trades between 28W-47W, and gentle winds north of 20N with 5-7 ft seas due to a northwest swell. The Cumbre Vieja volcano, on the island of La Palma in the Canary Islands, has been erupting since 19 September 2021. An ash emission is ongoing. Light to moderate volcanic ash is expected in the area east of the volcano, while high ash concentrations are in the vicinity of the volcano. Lower volcanic ash cloud is drifting to the southwest. 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 late Wed before dissipating Thu night. High pressure will shift east-southeastward across the western Atlc along 31N-32N through Thu, producing strong winds immediately north of the front. $$ Aguirre