000 AXNT20 KNHC 272356 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 756 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 1800 UTC surface analysis and satellite imagery through 2345 UTC. ...TROPICAL WAVES... A tropical wave is in the eastern Atlantic with axis extending from 08N26W to 01N26W, moving W at 10 kt. TPW imagery shows a moderate moist environment in the vicinity of the wave. Isolated showers are observed between 23W-28W. A tropical wave is in the central Atlantic with axis extending from 09N43W to 00N43W, moving W at 10-15 kt. TPW imagery shows a moderate moist environment, however Saharan dry air are hindering convection at the time. A tropical wave is in the west Atlantic with axis extending from 14N53W to 05N53W, moving W at 10 kt. Abundant moisture prevails within this wave as noted in TPW imagery. Isolated showers are noted within 100 nm on either side of the wave's axis. A tropical wave is over the east Caribbean with axis extending from 19N65W to 10N67W, moving W at 10 kt. Saharan dry air is present in the wave's environment inhibiting convection. ...ITCZ/MONSOON TROUGH... The Monsoon Trough enters the tropical Atlantic near 11N15W and continues to 05N22W. The ITCZ extends from 05N29W to 03N42W, then resumes W of a tropical wave near 03N45W and continues to 01N50W. Besides the convection associated with the tropical waves, isolated showers are observed within 100 nm on either side of both boundaries. ...DISCUSSION... GULF OF MEXICO... A 1020 mb high pressure center is located over NW Gulf near 28N85W supporting gentle to moderate anticyclonic winds across the basin. A thermal trough will develop over the Yucatan Peninsula in the evening hours and move west across the SW Gulf during the overnight hours. The trough will dissipate by the morning. This scenario will repeat through the weekend. CARIBBEAN SEA... A tropical wave is over the east Caribbean, however it lacks convection due dry air. See the Tropical Waves section for details. The proximity of the Monsoon Trough across the south-central Caribbean and upper-level divergence supports scattered showers south of 13N between 77W-83W. A broad area of high pressure centered over the west Atlantic extends over the remainder of the basin with little to no precipitation present at this time. This lack of convection is also related to Saharan dry air prevailing over this area. Scatterometer data depicts gentle to moderate trades across the northern portion of the basin while moderate to fresh easterly winds prevail south of 18N. Pulsing fresh to strong winds are expected over the Gulf of Honduras and north of Colombia tonight. Saharan dry air will continue to move W across the basin as seen in enhanced satellite imagery. ...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 significant convection at the moment. However, patches of low level moisture embedded in the trade wind flow could bring some cloudiness and isolated showers. Similar conditions are expected through the weekend. ...ATLANTIC OCEAN... Three tropical waves are located over the tropical Atlantic. Please refer to the Tropical Waves section for more details. A cold front extends across the west Atlantic from 31N63W to 25N78W. Isolated showers are observed along the front. Surface ridging prevails across the remainder of the basin anchored by a stationary 1023 mb high centered near 29N43W. For additional information please visit http://www.hurricanes.gov/marine $$ ERA