000 AXNT20 KNHC 050534 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Tue Oct 05 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 0000 UTC surface analysis and satellite imagery through 0510 UTC. ...SPECIAL FEATURES... The center of Hurricane SAM, at 05/0300 UTC, is near 47.7N 40.2W. Sam is moving toward the NNE, or 030 degrees, 25 knots. The estimated minimum central pressure is 965 mb. The maximum sustained wind speeds are 75 knots with gusts to 90 knots. The high seas forecast consists of maximum sea heights possibly reaching 50 feet. Precipitation: scattered moderate to isolated scattered strong is from 50N to 56N between 30W and 53W. Please, read the latest High Seas Forecast issued by the Ocean Prediction Center, at the website https://ocean.weather.gov/mobile/mobile_product.php?id=NFDHSFAT1, and the latest NHC Forecast/Advisory and Public Advisory, at www.hurricanes.gov, for more details. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 37W/38W, from 20N southward, moving W 10 to 15 knots. Precipitation: The majority of the widely scattered moderate to isolated strong precipitation, that is near the ITCZ also, is within 240 nm to the east of the tropical wave, and within 440 nm to the west of the tropical wave, from 04N to 11N. A Caribbean Sea tropical wave is along 77W/78W,from 17N southward, moving W 10 to 15 knots. An upper level trough is in the Atlantic Ocean, through 31N71W, across the central Bahamas, across SE Cuba, to 18N80W, to the Gulf of Honduras. Precipitation: widely scattered moderate to isolated strong is from 12N northward between 67W, and the line that extends from SE Cuba to 18N80W to the Gulf of Honduras. Other isolated moderate is elsewhere, to the west and northwest of the line from Cuba to the Gulf of Honduras. ...MONSOON TROUGH/ITCZ... The monsoon trough is mostly inland in Africa. A small part of the monsoon trough is along 12N/13N between the coast of Africa and 19W. The ITCZ is along 05N/07N between 21W and 36W. A north- to-south oriented surface trough is along 46W/47W, from 07N southward. Precipitation: widely scattered moderate to isolated strong is from 12N southward between 14W and 45W. Isolated moderate is elsewhere from 12N southward from 60W eastward. GULF OF MEXICO... A dissipating cold front extends from a 1012 mb SE Louisiana low pressure center, to 26N92W, and to the coast of Mexico near 22N98W. Precipitation: isolated moderate to locally strong is from 26N northward, and from 26N southward from 88W westward. Upper level cyclonic wind flow covers the area that is from 27N northward and to the northwest of the SE Louisiana 1012 mb low pressure center and the dissipating cold front. An upper level cyclonic circulation center is moving through south central Arkansas and north central Louisiana. Mainly light to gentle winds, and sea heights that range from 1 foot to 3 feet, span the area. Some moderate NE winds are offshore the western Yucatan Peninsula. Locally moderate NE winds are behind the cold front, offshore the lower Texas coast. A weak ridge north of the Gulf along 30N will move eastward through Wed, supporting tranquil conditions across the basin. A weak cold front over the NW Gulf will move slowly SE across the Gulf before stalling from the N central Gulf to central Bay of Campeche Wed then dissipating Thu. CARIBBEAN SEA... A tropical wave is along 77W/78W,from 17N southward, moving W 10 to 15 knots. An upper level trough is in the Atlantic Ocean, through 31N71W, across the central Bahamas, across SE Cuba, to 18N80W, to the Gulf of Honduras. Precipitation: widely scattered moderate to isolated strong is from 12N northward between 67W, and the line that extends from SE Cuba to 18N80W to the Gulf of Honduras. Other isolated moderate is elsewhere, to the west and northwest of the line from Cuba to the Gulf of Honduras. The eastern extension of the eastern Pacific Ocean monsoon trough is along 10N/11N, between 74W in Colombia, beyond Costa Rica, and into the eastern Pacific Ocean. Precipitation: numerous strong is in northern Colombia, from 06N to 11N between 72W and 76W. Isolated moderate is elsewhere from 12N southward from 70W westward. Strong trade winds, and sea heights that range from 7 feet to 10 feet, cover the central sections of the Caribbean Sea, as the gradient tightens between the Bermuda high and the east Pacific Ocean monsoon trough. Fresh trade winds, and sea heights that range from 6 feet to 8 feet, cover the eastern sections. Gentle to moderate trade winds, and sea heights that range from 3 feet to 5 feet, cover the rest of the basin. High pressure just N of Bermuda gradually will slide toward the east through the middle of the week. This pattern will produce fresh to strong trade winds across the NE and central Caribbean through Tue night. Fresh to strong trade winds will then persist across the central Caribbean Sea through Thu. Moderate N to NE swell from Sam will affect the tropical Atlc waters through Wed night. Winds and seas will diminish significantly by Fri. ATLANTIC OCEAN... An upper level trough passes through 31N71W, across the central Bahamas, across SE Cuba, to 18N80W, to the Gulf of Honduras. A surface trough curves along 28N71W 25N73W, to the Bahamas near 22N75W. Precipitation: scattered to numerous strong is from 90 nm to 180 nm to the east of the surface trough from 23N to 25N. Widely scattered moderate to isolated strong covers the waters that are elsewhere within 480 nm to the east of the surface trough, and from 30N northward between 76W and 80W. Upper level winds are not expected to be favorable for significant tropical development of this system, while it moves slowly northwestward during the next several days. The system is forecast to interact with a front that is near the coast of the southeastern United States, by the upcoming weekend. A surface trough is along 45W/47W, from 13N to 28N. This is the remnant of Victor, that weakened and dissipated at 04/1500 UTC. Precipitation: widely scattered moderate to isolated strong is from 21N to 24N between 46W and 50W. The Cumbre Vieja volcano, that is on the island of La Palma in the Canary Islands, has been erupting since 19 September at 1410 UTC. Marine and aviation interests should monitor this on-going situation, by reading the Volcanic Ash Advisory, that is issued by Meteo-France, at http://vaac.meteo.fr/volcanoes/la-palma/. Moderate to fresh trade winds cover the areas that are from 25N southward. Light to gentle winds are from 25N northward. Locally strong NE winds are occurring near the coast of NW Africa in an area of a tight pressure gradient. Fresh to locally strong winds are near the Leeward Islands. The sea heights are ranging from 6 feet to 8 feet. An area of sea heights that range from 8 feet to 10 feet is from 25N northward between 40W and 60W. High pressure just N of Bermuda will slide eastward slowly through mid week. This will produce moderate to fresh trade winds south of 24N and east of 73W through Tue before spreading into the southeast Bahamas Wed. The swell generated from Hurricane Sam will continue to impact the SW N Atlantic including the Bahamas through Wed night. Active weather is expected to continue through Tue night across the waters within 300 nm E of a surface trough from the SE Bahamas to 30N72W, as the trough shifts NW. $$ mt