000 AXNT20 KNHC 291743 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 143 PM EDT Sat Aug 29 2020 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 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1200 UTC surface analysis and satellite imagery through 1700 UTC. ...SPECIAL FEATURES... Atlantic Gale Warning: Meteo France has issued a gale warning for Agadir, off the coast of Morocco, valid now through 30/0000 UTC. See http://weather.gmdss.org/II.html for more information. ...TROPICAL WAVES... An eastern Atlantic tropical wave axis is along 25/26W from 05N-18N, moving W at 5 kt. Scattered moderate convection is within 120 nm E and 270 nm W of the wave axis from 07N-17N. The wave will move very slowly W for the next several days. Some development is possible next week, and there is a medium chance of tropical cyclone formation in the next 5 days. A tropical wave located over the central Atlantic, with axis along 42/43W from 06N-20N is currently in phase with a surface trough along 44W from 20N-26N. The tropical wave is moving W at 15-20 kt, while the sfc trough is moving W at 20 kt. Scattered moderate convection is within 210 nm E and 90 nm W of the wave axis from 07N-14N. A central Atlantic tropical wave axis is along 55/56W south of 19N, moving W at 20 kt. Scattered moderate isolated strong convection is within 150 nm of the wave axis from 12N-16N. Some gradual development of this system is possible while it moves W over the next several days, and it has a low chance of tropical cyclone formation in the next 2 days. Regardless of development, this system will likely produce gusty winds and locally heavy rain across portions of the Windward and Leeward Islands Sunday. A western Caribbean tropical wave axis is along 83W south of 18N, moving W at 10-15 kt. Scattered moderate isolated strong convection is occurring where the wave intersects the east Pacific monsoon trough, south of 14N between 77W-86W, including over portions of Nicaragua. The northern end of a tropical wave is in the SW Gulf of Mexico from 24N95W extending SSW to Mexico near 18N97W to the Pacific. The tropical wave is moving W near 10 kt. Low to mid-level southerly winds to the east of the wave axis are advecting very moist air into the south-central Gulf of Mexico. Scattered moderate showers and isolated tstorms are from 21N-25N between 92W-96W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Mauritania at 20N16W to the Cape Verde Islands near 16N24W to 13N30W to 13N46W. The ITCZ extends from 13N46W to 13N53W. The east Pacific monsoon trough extends from the Gulf of Venezuela near 10N72W to a 1010 mb low near 10N77W to the Costa Rica/Nicaragua border near 11N84W and west into the eastern Pacific. Aside from the convection associated with the tropical waves noted above, scattered moderate isolated strong convection exists south of the monsoon trough along the W coast of Africa from 08N-15N between 14W-21W. Scattered showers are seen 30 to 210 nm S of the ITCZ between 46W-53W. GULF OF MEXICO... Low to mid-level S-SW winds are advecting very moist air from the deep tropics, through the south-central Gulf to the NE Gulf and toward a mid-level trough over the eastern U.S. near the mid-Atlantic states. The moist air over the Gulf of Mexico shows up well on TPW imagery. Upper-level diffluence currently over the NE Gulf of Mexico is fueling numerous moderate isolated strong convection from 26N-31N between 84W-90W. Strong S-SW winds at the surface are seen over the NE Gulf with this activity. Additional convection is over the SW Gulf of Mexico, mentioned above in the tropical waves section. At the surface, an E-W ridge extends from the western Atlantic to the central Gulf along 25N, leading to gentle to moderate anticyclonic winds in the east-central Gulf. A recent ASCAT pass shows fresh SE to S winds in the south-central Gulf off the NW coast of the Yucatan peninsula. The ridge extending from the western Atlantic into the central Gulf will persist through early next week. A weak trough will move from the Yucatan peninsula across the west central Gulf through Sun. Fresh to locally strong SW winds are expected to continue through tonight over the north-central and northeast parts of the Gulf ahead of a cold front moving across the SE CONUS. CARIBBEAN SEA... A mid to upper level trough extends from the central Atlantic near 24N63W to the Mona Passage to Honduras. This, in combination with surface ridging extending over the western Atlantic and northern Caribbean, is producing stable atmospheric conditions and relatively dry air across much of the basin. Fresh to locally strong E winds are seen over the western Gulf of Honduras ahead of the tropical wave along 84W. Fresh to strong trades are noted in the central Caribbean north of Colombia. Seas are 4 to 6 ft over most of the basin, with up to 9 ft in the south central Caribbean. Trade wind convergence into the active monsoon trough is supporting a line of showers and tstorms from a 1010 mb low near 10N77W to central Nicaragua. Fresh trade winds will prevail over the central Caribbean through Sun, with locally strong winds expected to pulse near the coast of Colombia at night. Fresh to strong winds are also expected in the Gulf of Honduras through Sun night in the wake of a tropical wave moving through that area today. A second tropical wave, currently along 55/56W, will enter the eastern Caribbean late tonight or early Sun and reach the central Caribbean late Mon or Tue. Expect gusty winds and scattered showers with this wave. It has a low chance of becoming a tropical cyclone during the next few days. ATLANTIC OCEAN... An area of scattered moderate thunderstorms is seen over the W Atlantic north of 27N between 72W-77W. A surface ridge extends from a 1019 mb high pressure near 26N71W to South Florida. Ridging also extends east-northeastward from the high pressure to a 1023 mb high pressure near 35N34W. A dissipating stationary front extends from 32N52W to 29N58W. Scattered showers and isolated tstorms are along and within 120 nm NW of the front. A recent ASCAT pass shows that a westward moving surface trough, located along 44W from 20N-26N, has broad cyclonic turning with a large area of fresh NE winds to the west of the trough, and fresh E winds to the east of the trough. In the far NE Atlantic, a cold front is from 29.5N10W to the Canary Islands near 29N14W to 30N19W to 32N21W. Scattered showers are near the front. Strong NE winds are on both sides of the front and are covering much of the far eastern Atlantic. A ridge extending along roughly 25N will persist across the western Atlantic into early next week. A cold front will move off the southeastern U.S. coast tonight, then stall and weaken N of 28N early on Mon before dissipating. Moderate to locally fresh SW winds may precede the front this weekend over the waters N of 30N. A large trough, currently located along 44W, will reach the waters E of 65W by Sun night, crossing 65W by Mon night. Fresh to locally strong E to SE winds will follow this system. $$ Hagen