- NHC Atlantic Tropical Weather Discussion
by nhcwebmaster@noaa.gov (nhcwebmaster) on October 19, 2021 at 10:00 AM000 AXNT20 KNHC 191000 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 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 0600 UTC surface analysis and satellite imagery through 1000 UTC. ...TROPICAL WAVES... The axis of a tropical wave is near 30N from 02N to 16N, moving westward at 10-15 kt. Scattered moderate to isolated strong convection is from 04N to 07N between 28W and 32W. The axis of a tropical wave is near 49W from 02N to to 17N, moving westward at 10-15 kt. Scattered moderate convection is noted from 08N to 11N between 45W and 50W. The axis of a tropical wave is near 60W south of 20N, moving westward at 10-15 kt. Scattered moderate convection is noted from 10N to 15N between 55W and 60W. The axis of a tropical wave is near 84W south of 16N, moving westward at about 10 kt. Scattered moderate to isolated strong is near the northern part of the wave from 12N to 19N between 80W and 85W. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends off the coast of Senegal near 15N17W to 08N23W. The ITCZ continues from 08N23W to 06N28W. It then resumes near 06N31W to 07N43W to 06N47W. In addition to the convection mentioned above in the Tropical Waves section above, scattered moderate to isolated strong convection is noted from 04N to 08N between 24W and 28W, and from 04N to 07N between 32W and 45W. GULF OF MEXICO... A stationary front extends from the Straits of Florida to near 22N91W. Gentle to moderate winds prevail across much of the Gulf waters, except for the NW Gulf where light to gentle winds are noted. Seas are in the 3-5 ft range across much of the Gulf, except 1-3 ft over the NW Gulf. For the forecast, the stationary front from the Straits of Florida to 22N91W will slowly dissipate through Wed. Winds across the Gulf will gradually veer to the E today as high pres to the N slides eastward. Weak high pres will dominate the Gulf for the remainder of the week. CARIBBEAN SEA... A weak pressure pattern prevails across the Caribbean waters. Gentle to moderate winds are noted over the central and eastern Caribbean south of 13N as well as in the lee of Cuba. Light to gentle winds prevail elsewhere. Seas are in the 1-3 ft range across the Caribbean waters, reaching near 4 ft in the Yucatan channel. For the forecast, high pressure building N of the area will bring a return to moderate trade winds to the Caribbean today. Winds will further increase to moderate to fresh winds Wed through Sat. ATLANTIC OCEAN... A cold front extends from 31N56W to 24N72W, then becomes stationary to the straits of Florida. Farther east, a cold front enters the discussion waters from 31N25W to 26N30W, then becomes stationary to near 25N35W with a trough continuing westward to near 20N55W. High pressure of 1018 mb is centered south of the trough near 23N38W. Over the tropical waters south of 20N, trade- winds are moderate to fresh with seas in the 4-6 ft range. Over the tropical and subtropical waters north of 20N, gentle to moderate winds prevail. Seas over these waters are mainly in the 3-5 ft range. 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 frontal boundary that extends from 27N65W to the Straits of Florida will become stationary from near 25N65W to the Straits of Florida late Wed before dissipating Thu night. High pres will shift ESE across the W Atlc along 31N- 32N through Thu, producing moderate to fresh winds immediately north of the front. $$ AL