000 AXNT20 KNHC 201527 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Wed Oct 20 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 1630 UTC. ...TROPICAL WAVES... The axis of a tropical wave is near 37W from 12N southward, moving westward around 15 kt. No significant surface component of this wave is noted. Scattered moderate isolated strong convection is noted from 02N-09N between 24W-40W. The axis of a tropical wave is near 59W south of 18N, moving westward around 15 kt. No significant surface component of this wave is noted. Scattered moderate convection is noted from 10N- 12N between 56W-58W. The axis of a tropical wave is near 66W south of 20N, moving westward around 10 kt. The wave is identifiable from surface obs as well as the San Juan and Sint Maarten 700 mb rawindsonde winds. Isolated moderate convection is noted from 13N-19N between 54W-57W. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends off the coast of Senegal from 13N17W to 10N20W. The ITCZ continues from 10N20W to 04N40W. Scattered moderate isolated strong convection is noted from 02N- 09N between 24W-40W, from 03N-10N between 00W-10W, and from 08N- 10N between 48W-52W. GULF OF MEXICO... High pressure centered over the SE United States is inducing gentle to moderate E winds over the E Gulf with gentle and weaker winds elsewhere. Seas are 3-5 ft in the E Gulf and 1-3 ft in the W Gulf. A surface trough in the SW Gulf of Mexico is associated with isolated moderate convection south of 22N and west of 93W. Scattered moderate convection is also occurring north of 27N between 87W and 93W. For the forecast, the high pressure ridge will dominate the Gulf waters during the forecast period. Moderate to fresh easterly winds are expected over the north-central and NE Gulf today, and across the SE Gulf into Thu. Gentle to moderate winds will prevail elsewhere. CARIBBEAN SEA... A weak N-S pressure gradient is inducing only gentle to moderate trades across the Caribbean this morning. Seas are generally 3- 5 ft. Scattered moderate and isolated strong convection is noted in the NW Caribbean north of 16N and west of 82W. The eastern North Pacific monsoon trough extends eastward along 10N to a weak 1010 mb Colombia Low at 10N77W. Scattered moderate and isolated strong convection is occurring in association with the monsoon trough in the SW Caribbean south of 11N. For the forecast, high pressure building N of the area will bring fresh to locally strong trades E of the Windward Islands into Sun night. During this period, moderate to fresh winds are expected over the south-central Caribbean, with winds reaching locally strong in the Venezuela basin. Gentle to moderate tradewinds will prevail elsewhere. ATLANTIC OCEAN... A cold front extends from 31N52W to 27N59W where it transitions to a stationary front to 24N67W where that transitions to a trough to 23N73W. N to NE winds north of the front are moderate to fresh. Seas peak 8 to 10 ft north of 30N between 58W-62W in NW swell with seas 4-7 ft elsewhere. South of the front, the E trades are also moderate to fresh with seas 3-5 ft. Scattered moderate convection is noted within 60 NM of the front. A pair of weak troughs exist east and south of the front, though these have only moderate or weaker winds and no significant deep convection. A 1029 mb Azores High is driving moderate to fresh NE to E trades north of the ITCZ. Seas are generally 5-8 ft. The Cumbre Vieja volcano, on the island of La Palma in the Canary Islands, has been erupting since 19 September 2021. Ash emission is on-going. Moderate to high volcanic ash is expected in the vicinity of the volcano. Elsewhere, ash plume with weak concentrations drifting northwest. 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, a stationary front from 25N65W to the central Bahamas will gradually dissipate through Thu. High pressure building in the wake of the front will shift eastward across the W Atlantic along 31N-32N through Thu, producing moderate to fresh winds immediately north of the front. $$ Landsea