000 AXNT20 KNHC 230938 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 538 AM EDT Fri Jun 23 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 0600 UTC surface analysis and satellite imagery through 0930 UTC. ...TROPICAL WAVES... A tropical wave is in the E Atlc associated with a 1010 mb low centered S of the Cape Verde Islands near 13N24W. The wave axis extends from 19N22W to the low to 06N24W and it has been moving at 5-10 kt within the last 24 hours. The wave is in a region of favorable to neutral wind shear. However, the CIRA LPW imagery show extensive dry air around the low while moderate moisture with patches of dry air is S of the low. Meteosat enhanced imagery confirm the presence of Saharan dry air and dust around the low where there is lack of convection. Upper level divergence support scattered showers and tstms S of the low from 07N to 11N between 21W and 27W. A tropical wave is in the central Atlc associated with a 1010 mb low centered near 09N43W. Its axis extends from 14N43W to the low to 04N43W, moving W at 5 kt within the last 24 hours. The wave is in a region of favorable wind shear S of 11N, is mainly in a very moist environment with some patches of dry air according to CIRA LPW, and is under a region of upper level divergence. These factors support scattered heavy showers and tstms from 0N to 05N W of 41W, and isolated showers within 210 nm of the low center. A tropical wave is in the E Caribbean with axis extending from 16N62W to inland Venezuela, moving west at 5-10 knots within the last 24 hours. The wave is in a region of favorable to neutral wind shear. However, extensive intrusion of Saharan dry air and dust hinder convection at the time. A tropical wave is in the western Caribbean with axis extending from 21N84W to inland Honduras and Nicaragua, moving west at 20 knots within the past 24 hours. The wave is in a region of favorable to neutral wind shear. CIRA LPW imagery show patches of dry air ahead of the wave axis, which limit the convection to scattered to isolated showers S of 22N. Scattered showers and tstms are E of the wave axis from 13N to 22N between 78W and 85W. ...MONSOON TROUGH/ITCZ... The Monsoon Trough is not present over E Atlc waters. The Intertropical Convergence Zone begins near 08N25W to 04N40W to 04N51W. For information regarding convection see the tropical waves section. ...DISCUSSION... GULF OF MEXICO... Stable weather conditions are basin-wide being supported by surface high pressure extending SW from the W Atlc and dry air subsidence from aloft as indicated by Water Vapor imagery. Latest scatterometer data show fresh to strong S-SE winds in the northern Gulf N of 23N W of 88W. Fresh winds are also noted in the far W Bay of Campeche and in the Florida straits S of 24N. Moderate gentle to moderate SE winds are elsewhere. A tropical wave will enter the Yucatan Peninsula later today with scattered showers and thunderstorms. An upper level low ahead of this wave will move over the Bay of Campeche supporting heavy showers and tstms over the W Gulf W of 90W over the weekend. CARIBBEAN SEA... An upper-level low is centered over the NW Caribbean ahead of a tropical wave along 85W. Scattered heavy showers and tstms are E of the wave axis from 15N to 22N. See the tropical waves section for further details. The upper level low also supports scattered to isolated showers over western Cuba and across the Windward Passage. A 1009 mb low is over NW Colombia linked to the EPAC monsoon trough, which support isolated showers 120 nm off the Colombia coast S of 11N. Fresh to strong winds are in the vicinity of the wave while moderate trades dominate elsewhere. The upper- level low is forecast to move northwest toward the southwest Gulf of Mexico by Saturday with the tropical wave moving westward into the East Pacific waters during the weekend. Increased probability of convection and precipitation is expected across Central America and southern Mexico through this period. ...HISPANIOLA... Isolated showers and tstms are over SW Haiti and the Windward Passage associated with a broad upper level low over the NW Caribbean and a tropical wave moving across Honduras and the Yucatan Channel. An upper-level anticyclone centered N of the Bahamas continue to provide overall subsidence elsewhere, thus supporting fair weather across the remainder Island. ATLANTIC OCEAN... There are three tropical waves in the basin. See that section above for further details. Otherwise, the Azores high prevails across the basin being anchored by a 1025 mb high near 40N26W. A weakness in the ridge is being analyzed as a surface trough from 27N54W to 24N56W per the latest scatterometer pass. No significant areas of convection are occurring away from the ITCZ/monsoon trough/tropical waves. Little change is expected for the next couple of days. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos