000 AXNT20 KNHC 151737 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 137 PM EDT Sat Jul 15 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 1200 UTC surface analysis and satellite imagery through 1715 UTC. ...TROPICAL WAVES... A central Atlantic tropical wave has its axis from 13N46W to 04N48W, moving westward 10-15 knots. The wave has dry Saharan air well west of the wave axis as depicted in the latest METEOSAT-9 Saharan Air Layer imagery. Widely scattered moderate convection is within 120 nm of the wave axis. A Caribbean tropical wave has its axis from 19N68W to 08N70W, moving westward at 20 kt. Satellite imagery shows a well-defined cloud structure, with a low-level vorticity maximum on the southern portion of the wave axis near 14N. Scattered showers are within 120 nm of the wave axis. Some of the showers and may contain gusty winds. A Caribbean tropical wave has its axis from 20N80W to 09N81W, moving westward at 15-20 knots. The northern portion of the wave's axis is near the Cayman Islands. Subsidence aloft and some dry air is in the wave's environment. Scattered moderate convection is over the SW Caribbean from 07N-13N between 76W-83W, in vicinity of a monsoon trough. ...ITCZ/MONSOON TROUGH... The monsoon trough axis extends from 12N17W to 09N30W to 08N48W to 06N54W. Aside from the convection related to the tropical wave along 47W, widely scattered moderate convection is from 07N-13N between 15W-30W, and from 00N-12N between 34W-44W. ...DISCUSSION... GULF OF MEXICO... A surface trough is over the central Gulf of Mexico from 29N88W to 22N89W, moving W. Widely scattered moderate convection is over the north central and NE Gulf from 26N-30N between 83W-91W. In the upper levels, an upper level low is centered over the Bay of Campeche near 21N93W, with upper level moisture. Expect more convection over the N Gulf, and over the Bay of Campeche, over the next 24 hours. CARIBBEAN SEA... A couple of tropical waves are moving through the Caribbean Sea. See the section above for details. Aside from the convection related to these waves, an area of scattered moderate convection is near Lake Maracaibo Venezuela. Scatterometer data depicts gentle to moderate trades across the area. Expect additional convection over the W Caribbean and Central America over the next 24 hours. ...HISPANIOLA... Fair weather prevails across the island at this time. A tropical wave is approaching from the east. This wave will generate scattered convection and showers this evening through Sunday. ATLANTIC OCEAN... A tropical wave is moving across the central Atlantic. See the section above for details. A surface trough is analyzed over the Bahamas from 26N77W to 22N77W. Scattered moderate convection is within 90 nm of the trough axis. Another trough extends from 31N64W to 26N65W. Scattered showers are within 90 nm of this trough axis. The remainder of the basin is under the influence of a surface ridge, anchored by a 1026 mb high centered near 33N54W. Of note in the upper levels, an upper level low is centered near 28N67W enhancing showers. Expect additional convection over the W Atlantic and the Bahamas over the next 24 hours. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa