000 AXNT20 KNHC 170603 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 203 AM EDT Sat Aug 17 2019 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 0000 UTC surface analysis and satellite imagery through 0550 UTC. ...SPECIAL FEATURES... Potential for Heavy Rainfall/Flooding, from NW Venezuela and N Colombia to Central America and southern Mexico and the Yucatan Peninsula... Expect higher localized totals near strong topographical forcing. Flash floods and mudslides are the primary hazards during this event, which has been ongoing for the last few days. The GFS model for 250 mb, for 500 mb, and for 700 mb shows one inverted trough in the SW corner of the Caribbean Sea, and a second inverted trough from El Salvador southwestward into the eastern Pacific Ocean. Currently: Scattered moderate to isolated strong rainshowers cover the eastern Pacific Ocean and Central America from 12N to 17N between 87W and 94W, which includes parts of El Salvador, Honduras, Guatemala, and Mexico. Isolated to widely scattered moderate and locally strong rainshowers cover the Caribbean Sea from 70W westward. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 24W/25W, moving through the western part of the Cabo Verde Islands, from 17N southward, moving W 15 to 20 knots. Rainshowers are possible from 10N to 20N between 20W and 34W. A tropical wave is moving across the eastern islands of the Caribbean Sea, along 61W, from 17N southward, moving W 15 to 20 knots. This wave is well depicted in model guidance. widely scattered moderate to isolated strong rainshowers are from 06N to 15N between 50W and 60W. A Caribbean Sea tropical wave is along 81W/82W, from 20N southward, moving W 10 to 15 knots. A 1012 mb low pressure center is along the tropical wave near 11N. Isolated to widely scattered moderate and locally strong rainshowers cover the Caribbean Sea from 70W westward. The wave is moving through the areas of pre- existing upper level inverted troughs. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal border areas of Mauritania and Senegal near 16N17W, to 12N24W 08N32W and 08N39W. The ITCZ continues from 08N39W to 11N50W and 10N60W. Scattered moderate to isolated strong rainshowers are from 09N to 11N from 20W eastward. Scattered moderate to strong rainshowers are from 07N to 08N between 27W and 32W. Isolated moderate rainshowers are elsewhere within 120 nm on either side of the line that runs from 07N30W to 07N40W to 08N50W. The widely scattered moderate to isolated strong rainshowers, that cover the area that is from 06N to 15N between 50W and 60W, is to the east of the 61W tropical wave. GULF OF MEXICO... The GFS model shows a 700 mb inverted trough in the NE Gulf of Mexico near 28N90W. Upper level anticyclonic wind flow is on top of the NE corner of the Gulf of Mexico. Isolated to widely scattered moderate and locally strong rainshowers are from 24N northward from 92W eastward, and from 24N southward from 90W eastward. The current SE U.S.A. stationary front, with deep tropical moisture, continues to support the precipitation that is in the NE Gulf of Mexico. Some of this activity may contain gusty winds causing rough seas. Moderate to fresh southwest winds are expected in the NE Gulf of Mexico, ahead of the front through Sunday evening. Fresh to strong winds will pulse in the western Yucatan Peninsula adjacent waters through Monday. High pressure will build westward across the rest of the area early on Saturday, and it will prevail through Wednesday. CARIBBEAN SEA... The GFS model for 250 mb, for 500 mb, and for 700 mb shows one inverted trough in the SW corner of the Caribbean Sea, and a second inverted trough from El Salvador southwestward into the eastern Pacific Ocean. Scattered moderate to isolated strong rainshowers cover the eastern Pacific Ocean and Central America from 12N to 17N between 87W and 94W, which includes parts of El Salvador, Honduras, Guatemala, and Mexico. Isolated to widely scattered moderate and locally strong rainshowers cover the Caribbean Sea from 70W westward. Please read the SPECIAL FEATURES section for details about the potential for heavy/extreme rain amounts and flooding in Central America. An 81W tropical wave will continue to move across the western Caribbean Sea tonight and Saturday. The passage of this wave, along with high pressure to the north of the area, will continue to support fresh to near gale-force trade winds in the SW Caribbean Sea tonight, and in the NW Caribbean Sea on Saturday and Sunday. Fresh to strong winds will resume in the south central Caribbean Sea on Sunday evening, being supported by the passage of a new tropical wave that currently is across the Lesser Antilles. ATLANTIC OCEAN... Upper level cyclonic wind flow covers the area that is from 20N northward from 50W westward. An upper level trough extends from a 29N52W cyclonic circulation center, to 25N62W and 25N75W, beyond NW Cuba. A surface trough is along 60W/61W from 20N to 29N. Isolated to widely scattered moderate rainshowers are from 20N to 30N from 48W westward. A surface ridge extends from a 1026 mb high pressure center that is near 34N32W, to a 1027 mb high pressure center that is near 34N47W, to Bermuda, to 26N70W, across the Bahamas through the Straits of Florida, to 24N86W in the SE Gulf of Mexico. High pressure, currently dominating the forecast area, will begin to move northward as a trough races westward across the eastern and central forecast waters this weekend. This will maintain mainly gentle to moderate winds north of 22N, and moderate to fresh winds south of 22N, through most of the period. Fresh to strong winds are expected on Saturday in the NW forecast waters, due to a tighter pressure gradient between the ridge and a stationary front that is in the SE U.S.A. Fresh to strong winds will also pulse at night between the Turks and Caicos Islands and Hispaniola tonight, and then resume on Sunday evening and prevail through Monday evening. $$ mt