875 AXNT20 KNHC 021203 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 803 AM EDT Tue Oct 2 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 0600 UTC surface analysis and satellite imagery through 1115 UTC. ...SPECIAL FEATURES... Tropical Storm Leslie is centered near 31.6N 55.6W at 0900 UTC, or 470 nm E of Bermuda, moving SW at 6 kt. Estimated minimum central pressure is 989 mb. Maximum sustained winds are 55 kt with gusts to 65 kt. Scattered moderate convection is within 120 nm of the center in the northern semicircle, with weaker convection in the southern semicircle extending out to 180 nm. A slow southwestward or south-southwestward motion is expected through Wednesday morning. A turn to the north is forecast to occur late Wednesday into Thursday, followed by a motion toward the north-northeast on Friday. Gradual strengthening is expected during the next 48 hours, and Leslie is forecast to become a hurricane by Wed morning. Public Advisories for Leslie are the WMO header WTNT33 KNHC, and the AWIPS header MIATCPAT3. Forecast/Advisories for Leslie are the WMO header WTNT23 KNHC, and the AWIPS header MIATCMAT3. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 47W from 02N-14N, moving W around 15-20 kt. Scattered showers are near 09N-10N, where it intersects the ITCZ axis. An Atlantic Ocean tropical wave is along 59W from Guyana to 18N, moving W at 10-15 kt. The wave has a well defined 700 mb trough associated with it, but lacks significant convection. A TPW animation shows a moisture maximum is associated with this tropical wave. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near Senegal 10N20W to 09N35W. The ITCZ extends from 09N35W to 10N46W. The ITCZ resumes west of the tropical wave along 47W and continues to 09N58W. Scattered showers are along and within 60 nm south of the ITCZ axis between 36W-54W. ...DISCUSSION... GULF OF MEXICO... A surface trough is analyzed over the northeast Gulf along 84W from 25N-29N. The trough is producing scattered showers and thunderstorms over the eastern Gulf near the trough axis. A narrow upper-level trough axis located over the northern Gulf coast. This could help to enhance showers and thunderstorms today in the region. Expect ridging to prevail over the forecast area during the next few days. A surface trough will develop each evening over the Yucatan peninsula. The trough will move into the SW Gulf overnight, where it will dissipate each morning. Moderate to fresh winds will accompany the trough. CARIBBEAN SEA... A surface trough along 79W is associated with a broad area of low pressure located over the southwestern Caribbean Sea. Numerous strong convection is observed east of the surface trough from 12N-17N between 74W-78W. Elsewhere east of the surface trough, scattered moderate convection is present from 11N-18N between 73W-79W. Convection is being enhanced by upper-level diffluence east of an upper trough over the same region. Some gradual development of this system is possible late this week and this weekend while the low drifts generally northward during the next several days. Upper level troughing extends over much of the NW Caribbean Sea. Scattered showers are in the Yucatan Channel. Broad upper level ridging is over the east-central Caribbean with westerly upper level flow, leading to generally quiet weather conditions east of 71W. Large NNE swell generated from Leslie will pass through Atlantic passages into the Caribbean. ATLANTIC OCEAN... A broad mid to upper level trough in the vicinity of Leslie is helping to enhance convection to the southeast of Leslie. Scattered moderate convection is observed from 24N-29N between 42W-48W. Scattered showers and thunderstorms are occurring within 60 nm of a line from 24N66W to 25N75W. A cluster of convection, which is also being influenced by the broad upper trough, is occurring within 90 nm of 22N54W. Scattered showers and thunderstorms in advance of a tropical wave over west Africa are occurring east of 20W from 01N-15N. For additional information please visit http://www.hurricanes.gov/marine $$ Mundell/Hagen/Aguirre