000 AXNT20 KNHC 251014 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Mon Oct 25 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... A tropical wave is along 23W from 17N southward and it is crossing the Cabo Verde Islands. The wave is moving W at around 10 kt. A small area of moderate to isolated strong convection is in the wake of the wave from 12N-14N between 21W-23W. Another tropical wave is over the eastern Caribbean along 62W/63W, moving W at 10 to 15 kt. Aided by an upper-level trough in the vicinity, scattered showers and thunderstorms are noted over NE Venezuela and coastal waters as well as over Grenada and regional waters. A third tropical wave is along 76W and extends from eastern Jamaica to western Colombia, moving W at around 15 kt. The wave is helping to induce some shower activity over Colombia. Another tropical wave is over the Yucatan peninsula and Guatemala with axis along 90W. It is moving W at 10 to 15 kt. Convection is limited near the wave axis. ...MONSOON TROUGH/ITCZ... A monsoon trough exits through the African coast at Guinea-Bissau near 11N15W to 07N24W. The ITCZ then continues from 07N24W to 05N40W to near the coast of French Guiana at 04N52W. Scattered moderate isolated strong convection can be found from 07N-13N between 16W-20W, from 07N-09N between 30W-42W, and within about 30-60 nm on either side of the ITCZ W of 42W. Similar convection is from 02N-04N between 39W-43W. ...GULF OF MEXICO... Clusters of moderate to strong convection are noted over the SE Gulf and mainly SE of a line from near Tampa Bay, FL to 21N90W. A diffluent pattern aloft supports this convective activity that is spreading over South Florida. Strong southerly winds are seen on scatterometer data in association with this convection. Elsewhere across the eastern Gulf, mainly moderate E to SE winds prevail while mainly light to gentle winds are observed over the western Gulf. Seas are generally in the 2-4 ft range, except 1-2 ft over the Florida coastal waters, and in the Bay of Campeche. For the forecast, a ridge will dominate the Gulf waters producing gentle to moderate winds Mon through Tue. Fresh to strong southerly winds will develop in the NW Gulf Tue night into Wed ahead of a cold front expected to push off the Texas coast on Wed. The front will move across the Gulf region through Thu night. Fresh to strong winds are expected ahead and behind the front, with building seas to 10-12 ft in the wake of the front. Gusty winds to gale force may also occur, mainly over the north-central and NE Gulf Wed night to Fri as the pressure gradient tightens across the area. ...CARIBBEAN SEA... Two tropical waves are moving across the Caribbean Sea. Please, refer to the Tropical Waves section for more details. Aside from the convection associated with the waves, shallow moisture embedded in the trade wind flow is noted producing isolated to scattered passing showers. Fresh to locally strong winds are noted over the south-central Caribbean, including the Gulf of Venezuela. Moderate to fresh winds dominate the remainder of the east and central Caribbean, with the exception of light and variable winds over the SW portion of the basin. Mainly gentle to moderate winds are observed over the NW Caribbean. Seas are 6-8 ft over the south-central Caribbean, and 4-6 ft elsewhere. Fresh to strong trade winds and seas of 7-9 ft are E of the Windward Islands. For the forecast, a ridge N of the Caribbean Sea will support fresh to locally strong trades E of the Windward Islands and across the eastern Caribbean through tonight. Winds are also expected to pulse fresh to strong in the south-central Caribbean, including the Gulf of Venezuela through tonight. A cold front is expected to reach the NW Caribbean Thu night into Fri morning, with seas building to 8-9 ft in the Yucatan Channel later on Fri. ...ATLANTIC OCEAN... An area of moderate convection is noted just E of Florida and N of Cape Canaveral. A surface trough is analyzed there and extends from 31N74W to near Melbourne, FL. A low pressure is forecast to form in this area this morning. An area of showers and thunderstorms over the SE Gulf of Mexico is currently reaching the W coast of South Florida. Farther E, another trough extends from 28N41W to 20N45W. Patches of low level moisture with possible showers are in the vicinity of the trough axis. Most of the eastern Atlantic is under the influence of a 1029 mb high pressure located over the Azores. Fresh to locally strong trades are noted from 13N-22N E of 26W to the coast of Mauritania. Similar wind speeds are also observed E of the Windward Islands while a belt of mainly fresh trades dominates the waters N of the ITCZ/Monsoon trough to about 20N e of 40W, and to about 16N W of 40W. Seas of 6-8 ft are generally seen in association with these winds. The Cumbre Vieja volcano, on the island of La Palma in the Canary Islands, has been erupting since 19 September 2021. Ash cloud slowly drifting SW. Higher concentration over volcano and western vicinity. 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, a non-tropical low pressure system is expected to form off the east coast of the United States during the next day or so. The frontal low will move generally north- northeastward through the middle of the week, and the system will likely bring rain and wind impacts to portions of the mid-Atlantic and northeast U.S. coast. The associated cold front will move eastward across the northern forecast waters today. Fresh to strong southerly winds and building seas are expected ahead of the front. Another cold front will push off NE Florida coast on Tue, and bring more fresh to strong winds across the waters N of 27N. A third cold front is expected to sweep across the region Thu night through Fri night bringing another round of fresh to strong winds north of the Bahamas. $$ GR