000 AXNT20 KNHC 292341 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 741 PM EDT Sat Jul 29 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 2330 UTC. ...TROPICAL WAVES... A tropical wave is in the east Atlantic with axis extending from 17N28W to 07N28W, moving west at 10 kt. SSMI TPW imagery depicts the wave in an area of abundant moisture. Isolated showers are observed along the wave mainly south of the monsoon trough south of 11N between 26W-30W. A tropical wave is in the central Atlantic with axis extending from 18N43W to 06N43W, moving west at 10 kt. SSMI TPW imagery shows a narrow spike of moisture between 38W-45W. The wave is being severely affected by Saharan dry air and dust inhibiting convection. A tropical wave is in the central Atlantic with axis extending from 21N55W to 09N56W, moving west at 15 kt. The wave continues to be severely affected by Saharan dry air and dust intrusion to its environment. No significant convection is noted at this time. A tropical wave is in the central Caribbean with axis extending from 20N72W to 08N73W, moving west at 10 kt. The wave is in an environment where Water vapor imagery depicts dry subsident air over the wave also noticed in the CIRA LPW imagery. A tropical wave is over the Yucatan Peninsula and Central America extending its axis from in the west Caribbean with axis extending from 21N89W to 13N88W then into the Pacific to 06N87W, moving west at 15 kt. SSMI TPW imagery depicts the wave in an area of abundant moisture. An upper-level low is centered over western Cuba extending its trough west across the Yucatan Peninsula, helping in the generation of scattered moderate convection over the Yucatan and Central America. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from 12N16W to 11N29W to 08N45W. The ITCZ extends from 08N45W to 09N61W. Besides the convection mentioned in the Tropical Waves section above, scattered moderate convection is along and west of the coast of west Africa from 08N-16N and east of 23W. ...DISCUSSION... GULF OF MEXICO... A cold front is moving across the southeast U.S. and western Atlantic north of the area. The proximity of this boundary is generating cloudiness and isolated showers over the northern Gulf of Mexico waters and the Florida Peninsula mainly north of 27N and east of 95W. The northern portion of a tropical wave is moving across the Yucatan Peninsula. Please refer to the section above for details. The remainder of the basin is under the influence of a surface ridge that extends across the basin from the Atlantic. Scatterometer data depicts a light to moderate anticyclonic flow across the area, with highest winds along the northern portion of the basin north of 28N. Expect for the front to dip south over the northern Gulf waters during the next 24-36 hours with winds shifting to the north. Moderate to fresh northerly winds will prevail behind the front. CARIBBEAN SEA... Two tropical waves are moving across the basin. See the section above for details. The extension of the Pacific's monsoon trough is producing scattered moderate convection over the southwest Caribbean and portions of Central America mainly south of 12N. In the upper levels, an upper-level low is centered over western Cuba near 22N80W. Scattered showers and thunderstorms are observed in the periphery of this low affecting the western half of the basin mainly west of 72W. Scatterometer data depicts moderate to fresh trades with strongest winds over the south-central Caribbean. A similar scenario is expected during the next 24 hours. ...HISPANIOLA... Scattered showers are over western Hispaniola due to the northern extent of a tropical wave and afternoon heating. Similar activity is expected during the next 24 hours. ATLANTIC OCEAN... Three tropical waves are moving across the basin. See the section above for details. A broad and stationary 1027 mb surface high is centered over the central Atlantic near 33N42W supporting fair weather across the basin. The only area with a few showers is observed along the norther portion of a surface trough that extends from 29N60W to 22N60W. This trough is a reflection of an upper-level low centered near 30N57W. Little changes are expected for the rest of the weekend. For additional information please visit http://www.hurricanes.gov/marine $$ ERA