000 AXNT20 KNHC 200005 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 PM EDT Wed Jul 19 2017 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 2345 UTC. ...TROPICAL WAVES... A tropical wave is over the far eastern Atlc with its axis extending from near 14N20W to 05N21W, moving W at 5-10 kt within the last 24 hours. Saharan dry air and dust is in the wave environment according to enhanced satellite data. CIRA low to mid level moisture imagery show patches of dry air, thus confirming the presence of SAL. Shallow moisture, favorable to neutral wind shear and upper level diffluence support scattered moderate convection from 08N to 14N E of 27W. A tropical wave is in the central Atlc associated with a 1012 mb low near 12N46W. The wave axis extends from 21N44W to the low to 08N46W and it has been moving W at 15 kt within the last 24 hours. Intrusion of Saharan dry air and dust continue to affect the wave environment, which is limiting the convection to scattered showers from 10N to 14N between 45W and 49W. A tropical wave is over the eastern Caribbean Sea, which denotes the remnants of former Tropical Storm Don. The wave axis extends from 16N67W to 09N68W. The wave is in an unfavorable wind shear environment. However, abundant low to mid level moisture along with divergent flow aloft support scattered showers and tstms S of 15N between 65W and 72W. A tropical wave is in the central Caribbean with axis extending from 18N72W to 10N73W, moving W at 20 kt within the last 24 hours. CIRA LPW imagery depict abundant moisture associated with this wave that is in an unfavorable wind shear environment. With lack of lifting support from aloft, showers and tstms are only confined to northern Haiti. ...ITCZ/MONSOON TROUGH... The monsoon trough axis extends from 12N16W to 09N30W to 11N47W. The ITCZ then extends from 11N47W to 10N61W. Aside from the convection associated with the tropical waves, scattered moderate convection is from 05N to 12N between 25W and 37W. ...DISCUSSION... GULF OF MEXICO... Surface to middle level ridging is across the basin. At the surface, a 1019 mb high near 27N92W anchors the ridge that continues to provide gentle to light variable wind flow. An upper level trough along the SE CONUS supports a surface trough across Florida, which is generating heavy showers and tstms mainly in the northern and central peninsula. Numerous heavy showers and isolated tstms are over southern Mexico and the Yucatan Peninsula supported by a surface trough and upper level low centered just N of the Yucatan Peninsula. Otherwise, isolated showers are noted in the SW basin and over Louisiana coastal waters. No major changes are expected in this pattern for the next two days. CARIBBEAN SEA... The main features in the basin are the remnants of former tropical storm Don, currently analyzed as an open tropical wave, and a tropical wave in the central basin. Both features are discussed in the tropical waves section. See above for details. A potential tropical wave along with the EPAC extension of the monsoon trough support scattered heavy showers and tstms in the SW Caribbean S of 13N. Similar shower activity is along the S coast of Cuba being supported by shallow moisture and middle level diffluent flow. Otherwise, fresh to strong winds prevail across the central basin generally between 66W and 80W. Scattered moderate isolated strong convection over the SW Caribbean will remain quite active through Friday. ...HISPANIOLA... A fast moving tropical wave is moving across the western portion of the island. Scattered heavy showers and thunderstorms are noted over northern Haiti. These showers are expected to cease by Thursday morning as the wave races westward tonight. ATLANTIC OCEAN... As climatology dictates for this time of year, tropical waves are moving through the tropical Atlantic waters. See above for discussions on these features. A mid/upper level trough over the southeastern United States in combination with ample moisture and instability is resulting in scattered showers and thunderstorms over the SW Atlc N of 26N W of 72W. Otherwise, the remainder basin is under the influence of the Azores high anchored by a 1029 mb high N of the area. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos