000 AXNT20 KNHC 300928 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Sat Oct 30 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 0900 UTC. ...SPECIAL FEATURES... Showers continue to show some signs of organization near a strong, frontal low pressure system located several hundred miles south of Cape Race, Newfoundland. This non-tropical low is likely to lose its associated fronts while it moves southeastward toward slightly warmer waters during the next day or two, and it could make a transition to a subtropical storm this weekend or early next week over the central Atlantic. There is a medium chance of development for this system. For more detail information, please read the latest Tropical Weather Outlook issued by the National Hurricane center at this website: http://nhc.noaa.gov/gtwo.php?basin=atlc&fdays+2 The High Seas Forecasts issued by the National Hurricane and Ocean Prediction Centers can be found at this website: http://ocean.weather.gov/shtml/NFDHSFAT1.php ...TROPICAL WAVES... An Atlantic tropical wave is along 32W from 17N southward and moving W at 5 to 10 kt. Scattered moderate convection is noted from 11N to 15N between 27W and 30W. ...MONSOON TROUGH/ITCZ... A monsoon trough exits the Senegal coast near 14N17W to 1011 mb low pressure near 08N31W to 07N38W. Scattered moderate and isolated strong convection is noted from 04N to 15N between 12W and 27W. The eastern end of the eastern Pacific monsoon trough extends across Costa Rica to 1012 mb low pressure north of Colombia near 14N76W. Scattered moderate and isolated strong convection is noted southeast of the monsoon trough to the coast of Colombia, as well as from 11N to 15N between 69W and 76W. ...GULF OF MEXICO... A surface trough reinforcing the strong cold front that moved through the basin during the past couple of days reaches from near Tampa Bay, Florida to 24N75W. Scattered showers are seen from the central and north-central Gulf to the eastern Gulf including across portions of the Florida Peninsula. Satellite scatterometer data indicated fresh to strong W-NW winds north of 22N and 94W, with moderate to fresh winds elsewhere, except light to gentle offshore of Veracruz, Mexico to the western Bay of Campeche under a ridge axis. Large seas in W-NW swell of 8 to 18 ft remain north of 21N and east of 95W, with 5 to 8 ft elsewhere. For the forecast, fresh to strong winds north of 22N and east of 94W will diminish through the day. Large NW swell will gradually subside to below 8 ft by Sun. Fairly tranquil marine conditions are then forecast for the end of the weekend into next week. ...CARIBBEAN SEA... A slow moving cold front extends from central Cuba to across the NW Caribbean to the north-central coast of Honduras. Convection has sparked overnight with scattered showers and thunderstorms along and within 60 nm ahead of the front including across central Cuba, the Cayman Islands, and Honduras. Moderate to fresh winds continue west of the front, along with 5 to 8 ft seas, except 8 to 12 ft near the Yucatan Channel. Refer to the Monsoon Trough/ITCZ section for additional convection in the basin. Moderate to locally fresh trades and seas of 3 to 5 ft prevail across the eastern Caribbean to 73W, with light and variable winds and seas of 2 to 4 ft west of 73W to the front. For the forecast, the slow moving cold front will move through the NW Caribbean this weekend, before stalling Sun night from eastern Cuba to offshore Nicaragua. Moderate to fresh NW winds and seas of up to 12 ft can be expected in the wake of the cold front, especially in and near the Yucatan Channel. Elsewhere, a weak ridge over the northern Caribbean Sea ahead of the front will support mainly gentle to moderate trade winds across the basin, with locally fresh winds off the coast of Venezuela. ...ATLANTIC OCEAN... A slow moving cold front extends from 31N72W to across the central Bahamas to central Cuba. Scattered showers and thunderstorms are firing within 60 nm either side of the front. Moderate to fresh S-SW winds prevail ahead of the front to 68W as well as west of the front where a more defined wind shift is expected later behind a reinforcing trough which is currently moving into the area off the eastern coast of Florida. Another cold front extends from 31N49W to 27N55W to 25N63W with scattered showers and thunderstorms within 120 nm east-southeast of the front. Refer to the Tropical Waves and Monsoon Trough/ITCZ sections for additional convection in the basin. Moderate to fresh winds are within 300 nm either side of this front north of 25N. Seas are 7 to 10 ft north of 26N and west of 40W. 1015 mb high pressure is near 23N56W with a ridge extending westward along 23N, and east-northeast to 1018 mb high pressure west of the Canary Islands near 29N23W. Moderate to fresh trades prevail south of 25N between the coast of Africa and 35W, with light to gentle winds elsewhere. For the forecast west of 55W, the slow moving cold front will move slowly east and reach a Bermuda to eastern Cuba line by the end of the weekend. Fresh to strong winds are expected on both sides of the front through tonight, mainly north of 27N. Seas of 8 ft or greater will continue to fill in across the northern waters, lingering through Sun before decaying. The front will weaken as it stretches from 30N65W to the Turks and Caicos Islands Mon with gentle to moderate NE flow then prevailing into mid- week. The Cumbre Vieja volcano, on the island of La Palma in the Canary Islands, has been erupting since 19 September 2021. A volcanic ash cloud is slowly drifting south. High volcanic ash concentration remains in the vicinity of the volcano. Marine and aviation interests should monitor this ongoing situation by reading the Volcanic Ash Advisory issued by Meteo-France, at this website: http://vaac.meteo.fr/volcanoes/la-palma/. $$ Lewitsky