080 AXNT20 KNHC 011205 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 AM EDT Wed Aug 1 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 in the E Atlc with axis extending from 08N-18N along 26W, moving W at 10-15 kt. The wave continues to be severely affected by the Saharan Air Layer dry air and dust as depicted by GOES-16 RGBs and CIRA LPW imagery. This is hindering convection in the wave environment N of 11N. In the southern wave environment, the monsoon trough supports scattered moderate convection from 07N-11N between 20W-27W. A tropical wave is in the central Atlc with axis extending from 07N-18N along 41W, moving W at 10-15 kt. The wave is also being severely affected by Saharan Air Layer dry air and dust as depicted by GOES-16 RGBs, low-level water vapor and CIRA LPW imagery. No convection is associated to this wave N of 11N. In the southern wave environment, the monsoon trough and ITCZ support scattered moderate convection from 07N-10N between 38W-45W. A tropical wave in the central Atlc with axis extending from 06N- 17N along 57W, moving W at 10-15 kt. The wave is being supported by a mid-level inverted trough. A thin layer of dry air from a former SAL outbreak affects the northern wave environment. Abundant moderate moisture associated with the ITCZ and diffluece aloft support scattered moderate convection and isolated tstms from 08N-12N between 50W-63W. A tropical wave is in the west Caribbean with axis extending S of 21N along 81W, moving W at 10-15 kt. The wave is in a shallow moist environment that support scattered showers and tstms W of 80W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 20N16W and continues to 18N20W, then resumes near 09N27W to 08N34W to 08N40W. The ITCZ begins near 08N43W and continues to 08N56W. For information about convection, see the tropical waves section. ...DISCUSSION... GULF OF MEXICO... The Atlc subtropical high extends across the E basin supporting light to gentle southeasterly flow, except in the NE basin where convection enhance winds to moderate to fresh. CIRA LPW imagery show very moist air at low levels across the basin, which is being advected from the Caribbean by the return flow. This moist environment along with diffluence aloft supports scattered showers and tstms N of 23N E of 92W. A surface trough extends from 31N84W to 24N95W and is related to this convection. To the southwest, a thermal through currently extending over the Yucatan Peninsula is enhancing convection across the eastern portion of the Bay of Campeche. Showers are forecast to continue in the aforementioned regions through early Fri. CARIBBEAN SEA... Abundant shallow moisture is in the NW and central Caribbean as noted in CIRA LPW imagery. This moisture along with middle-to-upper level diffluence is supporting scattered showers N of 18N and west of 80W. An upper-level low off the E coast of Jamaica support scattered showers over eastern Cuba and the Windward Passage related also to a tropical wave. See the section above for details. Elsewhere, GOES-16 water vapor and RGB imagery show dry air and dust across the E basin, which in part is hindering the development of convection. A new tropical wave is forecast to move across the Lesser Antilles by Thu with showers for the Windward Islands. ATLANTIC OCEAN... Three tropical waves move across the basin, see the section above for details. Elsewhere, the Atlc subtropical high dominates the basin, supporting fair weather conditions. Surface ridging will dominate the basin through the next couple of days providing stable and dry conditions. For additional information please visit http://www.hurricanes.gov/marine $$ ERA/NAR