000 AXNT20 KNHC 161158 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 758 AM EDT Sat Jun 16 2018 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 0600 UTC surface analysis and satellite imagery through 1115 UTC. ...TROPICAL WAVES... A tropical wave is in the E Atlantic, with axis extending from 13N31W to 04N32W, moving W at 10 kt. The wave shows up well as a moisture surge in TPW imagery. Scattered moderate convection is noted from 6N-8N between 33W-35W. A tropical wave is in the central Atlantic, with axis extending from 15N47W to 04N48W, moving W at 10 kt. The wave is well depicted in the TPW product. Shallow moisture and isolated showers are observed near the wave's axis. A tropical wave is moving westward across the eastern Caribbean. Its axis extends along 66W. African dust surrounds the wave. As a result, shallow moisture with embedded showers is associated with the wave. This wave will move across the remainder of the eastern Caribbean through Sun, the central Caribbean Sun night through Tue and the western Caribbean Tue night through Wed night. A tropical wave is moving across Central America, with axis along 86W from 11N-18N, moving W at 10 kt. Scattered moderate to isolated strong convection is near the southern end of the wave's axis affecting parts of Nicaragua, Honduras, and El Salvador. The GFS model indicates plenty of moisture over Central America this weekend. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 14N17W to 11N232W. The ITCZ continues from 11N23W to 06N35W to 07N47W to 10N60W. Besides the convection mentioned in the Tropical Waves section, scattered moderate to isolated strong convection is from 5N-9N between 14W-18W. ...DISCUSSION... GULF OF MEXICO... A strong surface trough extends from 22N90W to the eastern Bay of Campeche. Fresh to locally strong winds are near the trough. A cluster of moderate to strong convection follows the trough covering the far NW Caribbean, the Yucatan Channel and the NE portion of the Yucatan Peninsula. Although environmental conditions are not expected to be favorable for significant development, heavy rains and gusty winds are likely to spread across the central Gulf of Mexico today and will reach portions of the Texas and southwestern Louisiana coasts on Sunday. The remainder of the Gulf is under the influence of a ridge. The trough will move west-northwestward towards the Texas coast through Sun. A tightening of the pressure gradient between the trough and high pressure that extends westward from the Atlantic to the eastern Gulf will induce fresh to strong southeast winds over the west-central Gulf waters this morning before becoming strong to near gale force by this afternoon over the central Gulf. These winds will spread westward through Tue while gradually diminishing. CARIBBEAN SEA... As previously mentioned, a cluster of moderate to strong convection covers the far NW Caribbean, including the Yucatan Channel. This convective activity is associated with a trough forecast to move across the Gulf of Mexico. Strong trades across the central Caribbean between 69W and 83W will slowly diminish through Sun night. The strongest winds will become confined to the S central waters, with similar pulsing winds continuing in the vicinity of the Gulf of Honduras. Two tropical waves are noted across the basin. Please, see Tropical Wave section for details. A tropical wave is forecast to reach the waters E of the Lesser Antilles Sun night through Mon night, and the eastern Caribbean Tue through Wed night. It is expected to be accompanied by scattered showers and thunderstorms. ATLANTIC OCEAN... High pressure of 1030 mb located just SW of the Azores extends a ridge across the forecast area. Three tropical waves are moving westward across the southern periphery of the ridge, that extends across Florida into the eastern Gulf of Mexico. A trough offshore northern and central Florida will be overtaken by a backdoor cold front today, which will drop southward through early next week. High pres ridging south of the boundaries will shift southward. Relatively weak high pres will build southward across the northern and central waters Tue through Wed night. For additional information please visit http://www.hurricanes.gov/marine $$ GR