836 AXNT20 KNHC 232348 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 748 PM EDT Sun Sep 23 2018 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 1800 UTC surface analysis and satellite imagery through 2345 UTC. ...Special Features... Tropical Storm Kirk centered near 9.5N 32.3W at 23/2100 UTC or 560 nm SW of the Southernmost Cabo Verde Islands moving W at 20 kt. Estimated minimum central pressure is 1006 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Some strengthening is forecast during the next day or two. Weakening is likely during the middle to latter part of the week. Scattered moderate isolated strong convection is from 06N-11N between 19W- 26W. See the latest NHC forecast/advisory under AWIPS/WMO headers MIATCPAT2/WTNT32 KNHC for more details. Subtropical Storm Leslie centered near 33.5N 47.2W at 23/2100 UTC or 1020 nm W of the Azores moving W at 3 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Scattered moderate convection is from 29N-34N between 45W-50W. Little overall motion is anticipated during the next 2 days. Some slight strengthening is possible, but Leslie is forecast to become absorbed by a larger non-tropical low by the middle of the week. See the latest NHC forecast/advisory under AWIPS/WMO headers MIATCPAT3/WTNT33 KNHC for more details. ...TROPICAL WAVES... A tropical wave extends its axis along 49W from 03N-16N, moving west at 10-15 kt. The wave corresponds nicely with a maximum in TPW imagery. Model analyses depict an associated 700 mb trough along 49W. Scattered showers are located from 09N-15N between 43W- 50W. A Central American tropical wave extends its axis along 92W from 08N-20N, moving west at 10 kt. The 700 mb trough associated with this wave is well depicted in model guidance, and TPW imagery shows abundant moisture in its environment. Scattered moderate convection is south of 20N between 89W-95W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the African coast near 09N13W to 08N22W. The ITCZ begins near 08N22W to 10N29W, then resumes west of T.S. Kirk near 07N35W to 06N47W. Aside from the convection associated with the tropical, scattered moderate convection is noted along the monsoon trough east of 18W. ...DISCUSSION... GULF OF MEXICO... An upper-level low is centered over the SE Gulf near 24N88W. Isolated moderate convection is E of 89W. An upper-level high is centered over N Mexico near 26N104W. Northerly upper-level flow is over the NW Gulf. A tropical wave is moving across the Yucatan Peninsula and entering the Bay of Campeche. Refer to the section above for details. At the surface, a cold front extends from E Texas near 29N94W to 26N95W to NE Mexico near 23N98W. A pre-frontal trough extends from SW Louisiana near 30N93W to 28N94W. Isolated moderate convection is N of 22N and W of 93W. A surface trough is over the Bay of Campeche along 94W. Scattered showers are S of 21N. Expect the front to stall and dissipate tonight. Gentle to moderate E to SE winds and seas 3 ft or less will prevail across most of the Gulf of Mexico through the middle of next week. A surface trough will develop over the Yucatan peninsula each evening, shift W over the SW Gulf each night, then dissipate by morning. Moderate to fresh winds will accompany this trough. CARIBBEAN SEA... The eastern Pacific monsoon trough combined with diffluence aloft continues to enhance scattered moderate to strong convection over the SW Caribbean S of 13N. Plenty of moisture will persist over the extreme southwest Caribbean, Panama and Costa Rica tonight. Elsewhere, fresh to strong winds prevail over the central Caribbean. These winds will diminish across most of the basin by tonight. ATLANTIC OCEAN... Currently, there is a tropical storm, a tropical wave, and a subtropical storm over the Atlantic. See above. A broad 1011 mb low is centered near 28N68W. A surface trough runs from 31N65W to the low center to 26N73W. Scattered showers are along the trough and near the low. Unfavorable upper-level winds and dry air are expected to limit development today, but conditions could become more conducive for some development of this system on Monday or Tuesday while it moves westward then west-northwestward over the southwestern Atlantic Ocean. By the middle of next week, strong upper-level winds are likely to limit additional development as the system turns northward and moves closer to the southeastern coast of the United States. This feature has a low chance of tropical cyclone formation during the next 48 hours. A weakening cold front is over the central Atlantic from 31N40W to 23N50W to 27N60W. Scattered moderate convection is within 90 nm of the front. The remainder of the basin is under the influence of a surface ridge, anchored by a 1030 mb high centered near 40N23W. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa/ERA