047 AXNT20 KNHC 311206 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 205 AM EDT tue Jul 31 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 1145 UTC. ...TROPICAL WAVES... A tropical wave is off the coast of Africa along 21W from 05N- 17N, moving west at 10-15 kt. A well defined surface trough is evident from scatterometer data, and a maximum in the total precipitable water imagery. Scattered moderate convection is in the southern wave environment from 05N-09N between 14W-27W associated with the monsoon trough A tropical wave is west of the Cabo Verde Islands along 32W from 07N-26N, moving west at 15-20 kt. A pronounced 700 mb trough in the GFS analysis is noted with this wave. No convection is associated with this wave. A tropical wave in the central Atlantic with axis along 47W from 02N-21N, moving west at 15-20 kt. Saharan Air Layer dry air and dust inhibit deep convection from developing at the time. A tropical wave is over the central Caribbean with axis along 72W, moving westward at 15-20 kt. Isolated convection is inland over Venezuela and Hispaniola. A tropical wave is along 95W, moving westward at 15 kt. Scattered moderate convection exists in the Bay of Campeche...heavy showers and tstms are E of the Gulf of Tehuantepec. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 15N17W to 10N21W to 09N32W. The ITCZ continues from 09N32W to the coast of South America near 06N58W, disrupted near 07N44W where it intersects a tropical wave axis. Scattered moderate convection is present from 05N-09N east of 25W. ...DISCUSSION... GULF OF MEXICO... A weak surface ridge and weak pressure gradient extends into the eastern Gulf from the W Atlantic. Winds are only 5-10 kt across the entire Gulf. An upper level trough is supporting widely scattered moderate convection in the southeastern Gulf. Winds will remain light during the next couple of days. Substantial moisture and upper-level trough forcing should contribute toward scattered moderate to strong deep convection over the Gulf during the next two days. CARIBBEAN SEA... The Bermuda high northeast of the Caribbean in combination with low pressure over Panama/Costa Rica associated with the monsoon trough in the NE Pacific supports a moderate pressure gradient over the Caribbean. Trade winds are 10-20 kt with highest winds around 25 kt just NW of Colombia. Scattered moderate convection is noted from 18N-21N between 78W-83W. In the SW Caribbean, the monsoon trough supports widespread showers south of 12N between 75W-83W. Little change expected during the next couple of days. ATLANTIC OCEAN... Three tropical waves moving across the basin are detailed above. The subtropical high dominates the basin. Isolated convection is observed in the W Atlantic N of 24N W of 77W. Surface ridging will dominate the central and eastern Atlantic through the next couple of days providing stable and dry conditions, except for scattered convection associated with the wave currently near 19W. For additional information please visit http://www.hurricanes.gov/marine $$ DM/NR