024 AXNT20 KNHC 151203 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 803 AM EDT Wed Aug 15 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. ...SPECIAL FEATURE... At 15/0900 UTC, the center of Subtropical Depression Five is located near latitude 37.6 North, longitude 45.6 West, about 882 nm W of the Azores. The estimated minimum central pressure is 1009 mb (29.80 inches). The subtropical depression is moving toward the north near 4 kt, and this general motion with a slight increase in forward speed is expected today. A faster northeastward motion is forecast to occur on Thursday and Friday. Maximum sustained winds are near 30 kt with higher gusts. Some strengthening is forecast during the next day or so, and the subtropical depression is expected to become a subtropical storm later today. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 36W, from 22N southward, moving W at 15 kt. Rainshowers are possible within 300 nm on either side of the wave. An Atlantic Ocean tropical wave is along 56W, from 20N southward, moving W at 15 kt. Scattered showers are from 15N-18N between 50W-60W. A Caribbean Sea tropical wave is along 74W from 21N southward, moving W at 15 kt. Scattered moderate convection is N of Jamaica from 18N-20N between 75W-78W. Scattered moderate to isolated strong convection is over N Colombia and NW Venezuela between 07N-12N between 70W-78W. A Caribbean Sea tropical wave is along 86W, from 23N southward, moving W at 15 kt. Scattered showers are within 120 nm of the wave axis. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Guinea- Bissau near 12N16W, to 11N18W, 10N20W, and then to 10N33W. The ITCZ is along 09N36W 08N43W 07N48W. Besides the convection mentioned in the tropical wave section, scattered moderate to isolated strong convection is from 05N-11N between 39W-47W. ...DISCUSSION... GULF OF MEXICO... NE upper level winds are over the Gulf of Mexico due to a large upper level high centered over N Mexico near 29N106W. At the surface, a 1022 mb high is centered over the W Atlantic near 30N70W. Surface ridging extends from the high to the NE Gulf of Mexico. Isolated moderate convection is over the NE Gulf from 25N- 29N between 83W-88W. Elsewhere, scattered moderate convection is over the Bay of Campeche from 17N-22N between 95W-98W. The surface ridge, extending westward from the Atlantic Ocean into the northern Gulf of Mexico will prevail across the region for the rest of the week. A nocturnal surface trough will move off the Yucatan Peninsula into the SW Gulf of Mexico each night, accompanied by a surge of fresh NE to E winds. CARIBBEAN SEA... Two tropical waves are over the Caribbean Sea. See above. An upper level trough passes over Andros Island in the Bahamas, to Belize in Central America. Isolated moderate rainshowers cover the area that runs from Haiti to Cuba, and from Honduras to Guatemala to SE Mexico into the SW corner of the Gulf of Mexico. Rainshowers are possible also from 15N northward from 80W westward, and elsewhere from 70W westward. An upper level cyclonic circulation center is about 100 nm to the north of the northern coast of Puerto Rico. Isolated moderate rainshowers are within 360 nm of the center in NE semicircle. The monsoon trough is along 08N/09N between 73W in Colombia and 84W in southern Costa Rica. Scattered moderate to isolated strong convection is over Panama, N Colombia, and NW Venezuela between 07N-12N between 70W-82W. A surface ridge across the western Atlantic Ocean will maintain fresh trade winds in the south central Caribbean Sea for the rest of the week. Moderate to fresh trade winds are expected elsewhere. ATLANTIC OCEAN... An upper level trough is along the coast of the SE U.S.A., passing through 32N76W to Andros Island in the Bahamas, to Belize in Central America. Isolated moderate rainshowers are to the NW of the line that runs through 32N70W to 28N80W along the Florida coast, from Haiti to Cuba, and from Honduras to Guatemala to SE Mexico into the SW corner of the Gulf of Mexico. Rainshowers are possible over the W Atlantic W of 73W to include the Bahamas. An upper level trough passes through 32N37W in the north central Atlantic Ocean, to 22N47W to 14N60W, just to the east of Martinique and Saint Lucia. Isolated moderate rainshowers are within 480 nm to the north of the trough between 49W and 60W. A surface trough passes through 32N48W to 26N56W. Isolated moderate to locally strong rainshowers are from 26N northward between 44W and 60W. Gentle to moderate trade winds, with a 30N surface ridge, will prevail across the region for the rest of the week. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa