000 AXNT20 KNHC 071059 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Thu Oct 7 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 0930 UTC. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 28W, from 16N southward, moving W at 10 to 15 knots. A large middle to upper level cyclone centered over the Cabo Verde Islands is strongly shearing this wave. Overcast multilayered clouds with scattered moderate convection extends from the eastern Cabo Verde from 24W eastward to 20W. Scattered to numerous moderate to strong convection is seen on both sides of the ITCZ S of 09N S of the wave described below. An Atlantic Ocean tropical wave is along 55W/56W, from 19N southward, moving W at 15 to 20 knots. A sharp middle to upper level trough is just NW of the wave along 59W/60W and N of 14N and is acting to sustain active convection associated with this wave. Scattered moderate isolated strong is from 09N to 14N between 51W and 59W, and S of 11N between 59W and 63W. A Caribbean Sea tropical wave is along 86W, from 19N southward, moving W at 10 to 15 knots. High pressure aloft across the NW Caribbean is providing favorable upper level conditions to sustain convection. Scattered moderate to strong convection is to the W and N of the wave from from 15N to 21N between 84W and 90W. Scattered moderate to numerous strong convection is also along the monsoon trough across the eastern Pacific Ocean from Costa Rica to 91W. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through coastal Gambia near 12.5N17W to 09N18W The ITCZ continues from 09N18W to 06N26W to 11N53W. Scattered to numerous moderate to strong convection is noted from 02N to 09N between 18W and 31W, within 210 nm NE of the ITCZ between 31W and 52W. GULF OF MEXICO... An upper level cyclone over the upper Mississippi River Valley and an upper ridge across the NW Caribbean combine to produce strong W to SW flow aloft across the entire Gulf basin. A weakening stationary front extends from near Pensacola, FL to the central Bay of Campeche. Isolated tstorms are seen along the front N of 27.5N, while scattered moderate isolated strong convection is on either side of the front S of 21.5N. Weak high pressure NW of the front is driving only gentle to moderate N to NE wind west of the front, except around 20 kt acrossthe area near Veracruz, Mexico. Gentle to moderate E to SE winds prevail E of the front. Seas are generally slight across the basin, except 4 to 5 ft offshore of Veracruz. The weakening stationary will meander today before drifting NW and gradually dissipating through Fri. Weak high pressure to the NW will support moderate to locally fresh northerly winds over Veracruz adjacent waters through Fri. High pressure will build modestly across the basin this weekend into early next week, and produce fresh return flow across NW portions Sun through Mon. CARIBBEAN SEA... A broad upper trough extends from Hispaniola northward across the Atlantic, while an sharp and narrow upper trough is along 60W to the N of 10N. A broad area of low to middle level moisture has converged to the N and E of the tropical wave along 86W, yielding active convection. Scattered moderate isolated strong convection is across the SW Caribbean S of 12.5N between coastal Colombia and coastal Nicaragua. Small widely scattered clusters of moderate convection are seen elsewhere inside the Caribbean. Fresh to strong trade wind prevail across most of central portions of the basin between 68W and 80W, where seas are 7 to 10 ft. Fresh trades and seas 5 to 6 ft prevail to the E. Fresh to locally strong trade winds across the majority of central Caribbean today will reduce coverage to across the south central Caribbean tonight behind the tropical wave exiting the western Caribbean. A tropical wave will move across the tropical Atlantic waters today through early Fri and weaken as it enters the E Caribbean Fri. A low level disturbance accompanied by strong winds, seas 8 to 10 ft, and very active weather will enter the tropical Atlantic waters early Fri and reach the central Lesser Antilles Fri morning. Strong upper level wind shear across the E and NE Caribbean during this time is expected to weakening this system as it moves westward across the E Caribbean Fri through Sat. ATLANTIC OCEAN... 1017 mb low pressure is centered along 31N80W, producing moderate winds and active convection to its N. Isolated clusters of moderate convection are seen to the E of this features from 30N northward between 73W and 77W. Gentle SE winds prevail between the low and 75W, where seas are 4 to 5 ft in NE swell. High pressure nudging into the SE Bahamas underneath the low is producing fresh to locally strong trade winds across the SE Bahamas, the Windward Passage and waters of eastern Cuba, where seas are 7-8 ft. 1022 mb high pressure is centered E of Bermuda near 36N51W. A lingering frontal trough stretches nearly E to W along 27N-28N across the central Atlantic between 42W and 60W, and is draped to the N across a surface trough along 62W. Scattered moderate to strong convection is seen within 90 nm either side of the frontal trough. Moderate to fresh trade winds prevail S of 22N across the tropical Atlantic, where seas are 7-10 ft in fading N swell. Active convection is S of 16N accompanying the tropical wave along 55W/56W. To the SE of the wave, a disturbance has developed along the ITCZ in the form of a surface trough along 49W, moving westward. Very active convection extends from this trough southeastward into the deep tropics along 31W, and is described above. Fresh to strong winds and seas locally 9-10 ft are seen just to the NE of this trough, in the vicinity of 14N49W. 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/. Weak low pres 1017 mb near 30.5N80W will drift northward and persist offshore of the SE U.S. coast through Sun. Fresh to strong trade winds across the SE Bahamas and Windward Passage will shift gradually westward and weaken through Fri morning. Otherwise moderate trade winds will prevail S of 25N through Sat. The low level disturbance along 49W will enter the tropical Atlantic waters early Fri and reach the central Lesser Antilles Fri morning before weakening as it moves westward across the E Caribbean Fri through Sat, and encounters strong upper level wind shear. High pres will build into the region Sun and Mon to produce moderate SE to S winds E of 75W. $$ Stripling