215 AXNT20 KNHC 180007 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 PM EDT Mon Sep 17 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 2315 UTC. ...SPECIAL FEATURES Tropical Depression Joyce is centered north of the area near 33.7N 27.4W at 2100 UTC or 260 nm S of the Azores, moving SE at 7 kt. Estimated minimum central pressure is 1008 mb. Maximum sustained winds are 30 kt with gusts to 40 kt. Joyce remains an organized low level circulation under strong westerly vertical shear, with minimal deep convection. It is expected to drift southward and gradually weaken through Wednesday. See the latest NHC forecast/ advisory under AWIPS/WMO headers MIATCPAT5/WTNT35 KNHC for more details. ...TROPICAL WAVES... A central Atlantic tropical wave is along 49W from 03N-18N, moving west at 15-20 kt. Model guidance indicates the wave is associated with a 700 mb trough. It is at the leading edge of an extensive area of dry Saharan air from 10N-25N between 15W-45W. Scattered moderate convection is south of 12N between 38W-54W. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends from W Africa near 14N17W to 10N20W. The ITCZ extends from 10N20W to 06N28W to 08N59W. Widely scattered moderate convection is from 07N-12N between 54W-60W. ...DISCUSSION... GULF OF MEXICO... An upper level low is over the western gulf near 25N94W. A 1016 mb surface high is over the NW Gulf near 27N93W. 5-10 kt anticyclonic winds are over the NW Gulf. 05-10 kt SE to S winds are over the remainder of the Gulf. The remnants of tropical cyclone Isaac, currently near Jamaica, will move west across Yucatan Channel on Wed and across the southwest Gulf waters on Thu. CARIBBEAN SEA... A weak low pressure area, associated with he remnants of Isaac, is located south of Jamaica. Showers and thunderstorms are limited, and environmental conditions are expected to become less conducive for any re-development to occur. Gentle trades are west of the remnants, while gentle to moderate trades are over the rest of the central and eastern Caribbean. A tropical wave along 49W is expected to reach the area Wednesday, accompanied by fresh trades and building seas. ATLANTIC OCEAN... Please refer to the Special Features section for details on Tropical Depression Joyce. Also refer to the tropical wave section for a wave along 49W. A broad deep layer trough extends across the central Atlantic from a large upper-level low centered near 27N65W. A 1013 mb surface low is near 25N66W with a trough extending southwest to near Hispaniola at 29N59W. The system is producing scattered showers and thunderstorms east of the trough axis between 20N- 30W and west of 50W. Well east of the trough, a 1024 mb high is centered near 28N39W. The surface trough and low are forecast to weaken over the next 24 to 48 hours as a ridge builds westward. For additional information please visit http://www.hurricanes.gov/marine $$ Mundell