000 AXNT20 KNHC 270000 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 800 PM EDT Fri May 26 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 Atlc with axis extending from 11N20W to 02N20W, moving W at 15 kt within the last 24 hours. The wave is mostly in a favorable wind shear environment. However, CIRA LPW imagery show a moderate moist environment with some large patches of dry air as the wave is being engulfed by the Saharan Air Layer. Scattered to isolated showers are from 01N-07N between 16W-26W. A tropical wave is in the central Atlc with axis extending from 10N34W to 01N34W, moving W at 20 kt within the last 24 hours. The wave is in an unfavorable to neutral wind shear environment and Saharan dry air intrusion is observed in satellite imagery. Scattered to isolated showers are from 01N to 07N between 30W-40W. A tropical wave is in the W Atlc with axis extending from 12N46W to 05N46W, moving W at 20 kt over the last 24 hours. Unfavorable wind shear and Saharan dry air across the wave environment hinder convection at the time. A tropical wave is SE of the Lesser Antilles with axis extending from 16N57W to 08N59W, moving W at 15 kt within the last 24 hours. Unfavorable wind shear and Saharan dry air across the wave environment hinder convection at the time. A tropical wave is in the SW Caribbean with axis extending from 14N80W to 06N81W, moving W at 5 kt within the last 24 hours. Favorable wind shear, the presence of abundant moderate moisture from the surface to the upper levels and the influence of the EPAC monsoon support numerous heavy showers S of 12N between 77W and 82W. ...ITCZ/MONSOON TROUGH... The Monsoon Trough enters the tropical Atlantic near 06N11W and continues to 05N13W. The ITCZ extends from 05N13W to 05N19W to 05N22W to 05N33W to 05N36W to 08N45W to 08N48W to 08N58W. No major areas of convection aside from the one associated with the tropical waves. ...DISCUSSION... GULF OF MEXICO... A 1018 mb high pressure it is located over adjacent waters of the Florida Big Bend near 29N84W supporting light to gentle winds across most of the basin, except W of 93W 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. A surge of fresh to locally strong winds will follow the trough. Little change in this weather pattern is expected over the upcoming weekend. CARIBBEAN SEA... A tropical wave is in the SW Caribbean supporting heavy showers S of 12N. See the Tropical wave section for more details. 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 68W and 80W. However, strong to near gale force winds are near the coast of Colombia. 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 at night through Saturday night. 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 as well as in Hispaniola. ...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, which is hindering convection at the moment. However, patches of low level moisture, embedded in the trade wind flow, could bring some cloudinees and isolated showers, particularly late Saturday into Sunday. ...ATLANTIC OCEAN... A former cold front in the SW N Atlc has stalled along 30N71W to 27N75W to 25N80W with scattered to isolated showers within 90 nm ahead of it. Over the NE portion of the basin, a cold front continues to weaken along 30N15W to 24N22W to 22N29W, which is expected to dissipate Saturday. A broad surface ridge dominates the remainder Atlc waters being anchored by a 1025 mb high near 30N50W, which is expected to move SE to near 28N44W by Saturday evening. Four 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. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos