000 AXNT20 KNHC 131718 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 118 PM EDT Fri Sep 13 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 1700 UTC. ...SPECIAL FEATURES... The center of Potential Tropical Cyclone Nine is centered near 25.0N and 74.5W at 13/1500 UTC, or 240 nm ESE of Freeport Grand Bahama Island, moving NW at 1 kt. Estimated minimum central pressure is 1009 mb. Maximum sustained wind speed is 25 kt with gusts to 35 kt. Scattered showers and thunderstorms are within 240 nm of the center in the E quadrant. On the forecast track, the system is anticipated to move across the central and northwestern Bahamas today, and along or near the east coast of Florida Saturday and Saturday night. The disturbance is forecast to become a tropical depression, or a tropical storm later today or Saturday. The chance of tropical cyclone formation during the next 48 hours is high. Please, read the latest NHC forecast/advisory under AWIPS/WMO headers MIATCPAT4/WTNT34 KNHC, or go to the website hurricanes.gov, for more details. ...TROPICAL WAVES... A tropical wave has been introduced to this analysis, with axis extending along 27N from 06N-20N. This wave has been moving west at around 10-15 kt. The wave is well depicted in satellite imagery and TPW imagery. Scattered moderate convection is developing in the wave's environment mainly south of 12N between 28W-32W. Conditions are expected to become more conducive for development in a couple days, and a tropical depression could form early next week while the system moves westward across the tropical Atlantic. A central Atlantic tropical wave extends its axis along 39W from 06N-20N, moving west at 10 to 15 kt. Scattered moderate convection is noted from 12N20N between 37W-43W. This wave is well depicted in model guidance and a satellite signature is noted. Conditions are expected to become more conducive for development in a couple days with this system also, and a tropical depression could form early next week while the it moves westward across the tropical Atlantic. Another Atlantic tropical wave is analyzed with axis along 53W, from 08N-21N, moving west at 10-15 kt. This wave was repositioned, based on satellite signature, TPW imagery and 700 mb streamline analysis. At this time, scattered showers are confined to the wave axis, mainly from 14N-17W. A west Caribbean tropical wave extends its axis along 81W from 07N-19N, moving west at around 10 kt. Numerous showers and thunderstorms are developing south of 13N between 78W-83W. This activity is enhanced by the presence of the monsoon trough, currently along 10N. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through coastal Africa near 17N17W to 07N43W. Aside from the convection already discussed in the Tropical Waves section above, scattered showers are noted along the boundary between 22W-28W. GULF OF MEXICO... An upper-level low is centered over the northeast Gulf, enhancing convection east of 90W. To the west, a surface trough extends across the Bay of Campeche from 23N97W to 20N94W. Scattered showers are noted along the trough. Scatterometer data depicts light to gentle winds across the western half of the basin, while gentle to moderate winds prevail east of 90W. High pressure over the southeastern United States will support moderate to fresh northeast to east winds into the weekend. Potential Tropical Cyclone Nine will track northwestward off the east coast of Florida through early next week. The gradient between the cyclone and the high pressure will allow for fresh winds over the NE Gulf today through Sat, along with building seas. Scattered showers and thunderstorms are expected across the eastern Gulf through Sun. CARIBBEAN SEA... Refer to the section above for details on the tropical wave moving across the west Caribbean. Scattered showers are noted over the Yucatan Channel and western Cuba. Aside from the convection related to the tropical wave over the southwest portion of the basin, fair weather prevails across the area. Scatterometer data depicts gentle to moderate trades across the basin, except locally fresh winds south of 14N between 68W-72W. High pressure north of the area will maintain moderate trades, that will at times pulse to fresh to strong in the south central Caribbean. The tropical wave will move across Central America on Sat. The next tropical wave will move across the eastern Caribbean on Sat. A third and stronger tropical wave will approach the eastern Caribbean over the weekend into early next week, expected to bring widespread showers and thunderstorms, gusty winds and building seas. ATLANTIC OCEAN... Refer to the sections above for details on the Potential T.C Nine, and the 3 tropical waves moving across the basin. Upper level cyclonic wind flow covers the area north of 25N between 50W and 64W. A surface trough is analyzed from 33N52W to 28N57W with scattered showers. Surface ridging prevails across the remainder of the basin with fair weather. Potential Tropical Cyclone Nine will move to 25.8N 76.5W this evening, 26.6N 78.0W Sat morning, 28.0N 79.4W Sat evening, 29.2N 80.0W Sun morning, and 31.0N 79.0W Mon morning. Nine will change little in intensity as it moves to near 31.5N 75.0W early Tue, and continue to near 32.0N 71.5W Wed. Elsewhere, the next tropical wave may approach the waters south of 22N by early next week. $$ ERA