000 AXNT20 KNHC 281001 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 601 AM EDT THU JUL 28 2016 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 1000 UTC. ...TROPICAL WAVES... A tropical wave is in the east Atlantic east of the Cape Verde Islands. The wave extends from 07N-15N with axis near 19W, moving W at 5 kt within the last 18 hours. The wave is associated with a 1011 mb low located near 10N19W and is being engulfed by Saharan dry air and dust, which have significantly reduced the convection associated with it. The CIRA LPW imagery show dry air from the surface to 850 mb in the northern wave environment, which is devoid of convection. A cluster of heavy showers is associated with the center of low pressure and extends from 08N-11N between 18W and 21W. Isolated showers are elsewhere from 07N-12N E of 23W. Some development of this system is possible during the next few days while it moves W or W-NW. A tropical wave is in the central Atlantic extending from 10N-20N with axis near 35W, moving at 15 kt within the last 24 hours. Meteosat composite imagery show Saharan dry air and dust in the wave environment. CIRA LPW imagery from the surface to 850 mb confirms dry air intrusion in the wave environment, which is keeping the wave devoid of convection. A tropical wave is in the central Atlantic from 08N-17N with axis near 46W, moving west at 15 kt within the last 24 hours. CIRA LPW imagery show mainly dry air from the surface to 850 mb associated with this wave. The dry air is due to the presence of abundant Saharan dry air and dust, which continue to hinder convection at the time. A tropical wave is in the west Caribbean from 12N-22N with axis near 81W, moving west at 25 kt within the last 24 hours. Aloft, water vapor imagery show strong dry subsidence across most of the SW Caribbean, which is inhibiting convection in that region of the wave. However, shallow moisture in the NW Caribbean and divergent flow aloft support isolated showers and tstms N of 17N W of 79W. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across Africa into the east Tropical Atlantic near 14N17W and continues to 10N30W to 09N40W to 08N48W where the ITCZ begins and continues to Venezuela near 08N60W. Aside from the convection related to the tropical waves, numerous heavy showers are from 06N-11N between 26W and 38W. ...DISCUSSION... GULF OF MEXICO... A broad inverted upper-level trough covers the W Gulf of Mexico. This feature along with shallow moisture across the basin support isolated showers and tstms N of 22N W of 90W. The SW periphery of a middle to upper level anticyclone covers the E-NE portion of the basin. Diffluent flow generated by the two upper level features support scattered heavy showers and tstms across the SE Gulf and isolated showers N of 26N. A surface trough is off the W Yucatan Peninsula supporting isolated showers S of 21N E of 93W. Otherwise, weak surface ridging is elsewhere being anchored by a 1018 mb high in the NE basin near 29N84W. Scatterometer data depicts gentle to moderate return flow across most of the Gulf. A tropical wave currently over the W Caribbean will enter the Yucatan Peninsula tonight and move into the Bay of Campeche Friday. Weak surface pressure and return flow will prevail elsewhere for the next two days. CARIBBEAN SEA... A tropical wave is in the west Caribbean from 12N-22N with axis near 81W. Aloft, water vapor imagery show strong dry subsidence across most of the SW Caribbean, which is inhibiting convection in that region of the wave. However, shallow moisture in the NW Caribbean and divergent flow aloft support isolated showers and tstms N of 17N W of 79W. In the SW basin, the monsoon trough supports heavy showers and tstms S of 11N. Water vapor and CIRA LPW imagery show dry stable air across the remainder basin, which is supporting fair weather. Fresh to strong trade winds continue across the central Caribbean between 68W and 80W, which are expected to amplify west and continue through the weekend. The next tropical wave will enter the east Caribbean by early Friday. ...HISPANIOLA... Hispaniola continue to enjoy fair weather this morning as stable deep layer dry air moves across the Island. Haze and dust are being reported in the N and SE portions Dominican Republic due to the presence of Saharan air in the region as indicated by Meteosat composite imagery. Except for afternoon showers to be concentrated over the central and western portions of the Island, fair weather is expected through Friday. ATLANTIC OCEAN... Three tropical waves are moving across the basin. Please refer to the tropical waves section for more details. In the SW N Atlantic, a 1017 mb high is located near 26N70W. To the east of the high center, scattered heavy showers and isolated tstms are noted from 25N-28N between 65W and 69W. The remnants of a stationary front are now analyzed as a surface trough from 30N58W to 26N63W with isolated showers within 60 nm E of its axis N of 26N. Surface high pressure is across the remainder basin being anchored by a 1031 mb high centered N of the Azores Islands. Little change is expected through the next 48 hours. For additional information please visit http://www.hurricanes.gov/marine $$ RAMOS