000 AXNT20 KNHC 271800 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 200 PM EDT Sat May 27 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 1200 UTC surface analysis and satellite imagery through 1745 UTC. ...TROPICAL WAVES... A tropical wave is in the eastern Atlc with axis extending from 08N24W to 02N24W, moving W at 10 kt. CIRA LPW imagery shows a moderate moist environment in the vicinity of the wave where wind shear shows to be favorable. This along with upper level diffluence support scattered showers from 03N-10N between 14W-28W. A tropical wave is in the central Atlc with axis extending from 09N36W to 01N37W, moving W at 10 kt. CIRA LPW imagery shows a moderate moist environment, however Saharan dry air and dust as well as unfavorable wind shear hinder convection at the time. A tropical wave is in the W Atlc with axis extending from 12N49W to 03N50W, moving W at 15 kt. CIRA LPW imagery shows dry air ahead of the wave that along with unfavorable wind shear hinder convection at the time. A tropical wave is over the E Caribbean with axis extending from 18N62W to 10N64W, moving W at 15-20 kt. Unfavorable wind shear and Saharan dry air across the wave environment is hindering convection at this time. ...ITCZ/MONSOON TROUGH... The Monsoon Trough enters the tropical Atlantic near 10N14W and continues to 05N23W. The ITCZ extends from 05N26W to 04N35W, then resumes W of a tropical wave near 03N39W and continues to 0N50W. Besides the convection associated with the tropical waves, scattered moderate convection is from 10N-15N between 52W-60W. ...DISCUSSION... GULF OF MEXICO... A 1019 mb high pressure center is located over NW adjacent waters of Tampa near 28N84W supporting light to gentle winds across most of the basin, except W of 91W where moderate return flow dominates. A thermal trough will develop over the Yucatan Peninsula during the evenings, move west across the SW Gulf during the overnight hours and dissipate near 94W by late each morning through Monday. A surge of fresh to locally strong winds will follow the trough. Little change in this weather pattern is expected through Monday. CARIBBEAN SEA... A tropical wave is over the E Caribbean, however it lacks convection due to deep layer dry air and unfavorable wind shear. See tropical waves section. This same environment is across the remainder basin, except in the SW Caribbean where favorable wind shear, abundant moisture and upper level divergence support scattered moderate convection S of 13N between 75W and 83W. Otherwise, high pressure over the central Atlantic extends a ridge SW across the northern Caribbean Sea, which supports fresh to strong easterly winds across the south-central Caribbean between 74W and 77W. Gentle to moderate trades are elsewhere. The strong winds in this region are expected to continue through early next week. Pulsing fresh to strong E to SE winds are expected over the Gulf of Honduras tonight. Moderate to locally fresh trades are expected elsewhere. Saharan dry air and dust continue to move across the basin as seen in enhanced satellite imagery. This dust continue to be reported in the Lesser Antilles, Hispaniola and Jamaica while hazy conditions are being reported across Central America. ...HISPANIOLA... Saharan dust continue to be reported across the Island and is observed in satellite enhanced imagery. Water vapor imagery show strong subsidence over the Island as well, which is hindering convection at the moment. However, patches of low level moisture, embedded in the trade wind flow, could bring some cloudiness and isolated showers, particularly late today into Sunday. ...ATLANTIC OCEAN... A cold front in the SW N Atlc extends along 30N63W to 28N71W to 25N77W with scattered showers and tstms within 90 nm ahead of it. West of the front, a 1019 mb center of high pressure developed near 29N79W, which is expected to dissipate by Sunday morning. A broad surface ridge dominates the remainder Atlc waters being anchored by a 1024 mb high near 30N48W, which is expected to move SE to near 27N41W by Sunday morning. Three tropical waves are located over the tropical Atlantic between the west coast of Africa and the Lesser Antilles. Please refer to the Tropical Waves section for more details. Saharan dry and dust is noted across much of the Atlantic Ocean. A new cold front will dip into the central Atlc between 25W-40W tonight. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos