000 AXNT20 KNHC 161735 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Sat Oct 16 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 1200 UTC surface analysis and satellite imagery through 1700 UTC. ...SPECIAL FEATURES... Atlantic Gale Warning: A 1001 mb low pressure center is located near 35N38W. A cold front extends from the low to 26N50W, then a trough continues from that point to 23N63W. A tight pressure gradient between the front and a surface ridge to the east is supporting minimal gale force winds east of the front. Seas over the gale area are currently reaching near 15 ft. The low pressure area will continue to shift further NE away from the area, with the gales moving north of the area by tonight. Gulf of Mexico Gale Warning: A cold front extends over the NW Gulf of Mexico from 30N88W to 23N98W. The front will continue to spread southeast across the Gulf waters this weekend. Fresh to strong winds are currently west of the front. Winds will increase to gale force this afternoon over the waters off Tampico, Mexico. These winds will spread southward, extending off the coast of Veracruz, Mexico on Sun. Seas will peak near 13 ft off Veracruz, Mexico by Sun afternoon. Please read the latest High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details on both warnings. ...TROPICAL WAVES... The axis of a tropical wave is near 36W south of 18N, moving W at 10 to 15 kt. This mornings scatterometer data depicted a decent curvature with this wave. Scattered moderate convection is from 01N to 10N between 30W and 42W. The axis of a tropical wave is near 49W south of 19N, moving W at 10 to 15 kt. No significant convection is related to this wave at this time. The axis of a tropical wave is near 70W south of 20N, moving W at 10 to 15 kt. Scattered moderate to strong convection is developing over the southern portion of the wave currently extending across western Venezuela/eastern Colombia. The axis of a tropical wave is near 83W south of 19N, moving W at 10 to 15 kt. Scattered moderate convection is noted S of 13N between 75W and 85W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 13N17W to 06N23W. The ITCZ continues from 06N23W to 06N34W. It resumes from 05N38W to 06N47W, and then from 06N52W to 07N58W. Aside from convection mentioned in the Tropical Waves section, scattered moderate convection is noted from 01N to 13N between 18W and 47W. GULF OF MEXICO... Refer to the Special Features for information on the Gale Warning in effect for the SW Gulf of Mexico. Aside front the cold front described above, a pre-frontal trough extends from 30N83W to 26N87W. Scattered showers are noted S of 26N and W of 90W. Weak high pressure prevails over the remainder of the basin. Light to gentle winds prevail SE of the front with seas of 1-3 ft. For the forecast, the cold front will continue moving SE across the basin. Winds will gradually veer from the E Mon through Tue as the front becomes aligned W to E along 23N and dissipates. CARIBBEAN SEA... Please refer to the section above for details on the tropical waves moving across the basin. A weak pressure pattern prevails across the Caribbean waters. Gentle to moderate winds and seas of 3-4 ft are over the central and eastern Caribbean waters south of 14N. Light to gentle winds and seas of 1-3 ft prevail across the remainder of the Caribbean waters. For the forecast, a very weak pressure gradient between the W Atlc and the Caribbean basin will lead to tranquil marine conditions through early Mon. A cold front will enter the NW Atlc over the weekend and move SE. High pres building in the wake of the front will bring a return to moderate trade winds to the Caribbean Mon night. ATLANTIC OCEAN... Please refer to the Special Features section above for details on the Gale Warning and tropical waves currently across the basin. A 1011 mb surface low is centered near 30N66W. A surface trough extends from the low to 25N67W. No significant convection is related to these features at this time. To the east, scattered moderate convection prevails N of 18N between 37W-59W related to the gale front/trough. Aside from the gale conditions east of the front/trough, gentle to moderate winds and seas of 4-6 ft are found N of 20N and E of 60W. W of 60W, light to gentle winds prevail. Seas W of 60W are in the 3-5 ft range over the open waters, and 1-3 ft west of the Bahamas. Over the tropical waters south of 20N, moderate to fresh winds and seas of 5-7 ft are noted. The Cumbre Vieja volcano, on the island of La Palma in the Canary Islands, has been erupting since 19 September 2021. Low ash concentrations moving NW. 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 W of 65W, weak pres pattern prevails today across the W Atlantic to the SW of Bermuda. A cold front will move southeastward off the SE U.S. coast Sat night and all of across Florida by Sun night, reaching from Bermuda to the Florida Keys by Mon morning. Expect fresh to strong N to NE winds behind the front through Mon morning. $$ ERA