000 AXNT20 KNHC 141804 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 204 PM EDT Sat Sep 14 2019 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 1745 UTC. ...SPECIAL FEATURES... Tropical Storm Humberto is centered near 26.6N 76.7W at 14/1500 UTC or 30 nm ENE of Great Abaco Island. Humberto has barely moved this morning remaining stationary with a minimum central pressure of 1005 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Scattered moderate isolated strong convection extends outward 180 nm NE and E quad. Numerous moderate to scattered strong convection extends outward 270 nm SE quad. Little to no convection is in the western semicircle. On the forecast track, the center of Humberto should gradually move away from the northwestern Bahamas later today or tonight, and then will move well offshore of the east coast of Florida this weekend and early next week. Humberto is forecast to become a Hurricane by Sunday night well east of the east coast of Florida. Please read the latest NHC forecast/advisory under AWIPS/WMO headers MIATCMAT4/WTNT24 KNHC, or go to the website hurricanes.gov for more details. ...TROPICAL WAVES... An eastern Atlantic tropical wave is along 34W from 05N-15N, moving W at 15-20 kt. The wave is well depicted in satellite imagery and TPW imagery. Scattered moderate convection is from 06N-12N between 32W-36W. Gradual development of this system is possible during the next several days, and a tropical depression could form early next week while it moves westward across the tropical Atlantic. A central Atlantic tropical wave is along 46W from 20N southward, moving W at 15-20 kt. Scattered showers are within 180 nm west of the wave axis from 12N-17N. This wave is well depicted in model guidance, and satellite imagery shows turning. Conditions could become a little more conducive for development in a few days when the wave moves over the eastern Caribbean Sea. An Atlantic tropical wave is along 57W, from 21N southward, moving west around 15 kt. Scattered moderate convection is within 100 nm of the wave axis from 13N-17N. TPW imagery and 700 mb streamline analysis depict the wave well. A western Caribbean tropical wave is along 87W from 18N southward, moving W around 15 kt. Scattered showers are over the Gulf of Honduras, and over portions of Central America. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from Guinea-Bissau near 12N16W to 09N20W to 08N42W. The ITCZ is from 06N49W to 04N56W. Aside from the convection already discussed in the Tropical Waves section, an area of moderate isolated strong convection embedded in the monsoon trough extends 180 nm North between 21W-33W. This elongated area of disturbed weather is being monitored with a low chance of tropical cyclone formation during the next 48 hours. An area of scattered moderate convection, associated with a surface trough, is just N of the ITCZ from 08N-11N between 49W-54W. Elsewhre, scattered showers are within 100 nm N of the ITCZ. GULF OF MEXICO... The weather over the Gulf of Mexico is dominated by a large upper-level low that is centered over the central portion of the basin near 25N91W, but spans nearly the entire Gulf. Upper-level diffluence on the east/northeast side of the upper low is producing numerous moderate isolated strong convection from 24N-29N between 82W-91W. Only slow development of this system is likely during the next couple of days. However, conditions could become more conducive for development early next week as the system moves over the western Gulf of Mexico. Elsewhere across the basin, scattered showers and tstorms are seen near the coast of Mexico from 18N93W to 24N97W. The latest ASCAT pass shows moderate to fresh ENE winds across much of the Gulf. A large area of showers and thunderstorms over the eastern Gulf of Mexico is primarily associated with a upper-level low. Only slow development of this system is likely during the next couple of days. However, conditions could become more conducive for development early next week as the system moves over the western Gulf of Mexico. Fresh to locally strong NE to E winds will persist over the eastern Gulf today, between high pressure over the Mississippi Valley and Tropical Storm Humberto near the Bahamas. Winds and seas will diminish tonight into Sun as Humberto moves away from the eastern coast of Florida. CARIBBEAN SEA... Refer to the Tropical Waves section above for details on the tropical wave moving across the western Caribbean. Relatively dry air covers much of the Caribbean Sea, including the central Caribbean. In the SW Caribbean, a line of scattered moderate strong convection extends from the NW coast of Colombia to the coast of Nicaragua, from 08N-16N between 76W-83W. Surface trough extends north of Cuba and the NW Caribbean from 23N79W to 21N86W. Scattered showers and tstorms are also seen over the NE Caribbean due to an approaching tropical wave. The latest ASCAT pass shows fresh trades over the south-central Caribbean, south of 16N between 64W-77W. Moderate to fresh trade winds will dominate much of the basin, with fresh to strong winds in the south-central Caribbean through Sun. A tropical wave over the Gulf of Honduras will move inland today. Another tropical wave nearing Barbados will move across the eastern Caribbean tonight and Sun, reaching the central Caribbean on Mon. A third and stronger tropical wave will approach Barbados late on Sun, move across the eastern Caribbean Mon, and into the central Caribbean through mid week, bringing widespread showers and thunderstorms, gusty winds and building seas. Northerly swell will reach the Atlantic passages into the Caribbean Sea late on Mon. ATLANTIC OCEAN... Refer to the sections above for details on T.S. Humberto and the three tropical waves moving across the basin. Upper-level troughing covers the area north of 23N-59W to 31N53W. Upper-level diffluence near the base of this trough is giving way 21N-24N between 60W-63W with a trough at the surface 23N66W to 28N61W. Some additional showers are seen within 150 nm of a line extending from 23N57W to 28N51W to 31N49W due to low-level troughing and upper-level diffluence in the area. Surface ridging and fair weather cover E Atlantic north of 20N and east of 40W. Tropical Storm Humberto will move to 27.6N 77.6W this evening, 28.7N 78.1W Sun morning, strengthen to a hurricane near 29.5N 78.0W Sun evening, 30.0N 77.0W Mon morning, and 30.5N 74.5W Tue morning. Humberto will change little in intensity as it moves to the near 31.5N 70.0W early Wed, and continue to near 34.5N 63.0W on Thu. The center of Humberto should gradually move away from the NW Bahamas later today or tonight, and then will move well offshore of the east coast of Florida this weekend and early next week. Humberto is forecast to become a hurricane by Sunday night well east of the east coast of Florida. Northerly swell will reach the Atlantic passages into the Caribbean Sea late on Mon. $$ Torres