000 AXNT20 KNHC 181001 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 601 AM EDT Tue Apr 18 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 0600 UTC surface analysis and satellite imagery through 1000 UTC. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across the western Africa coast near 11N16W and continues to 02N21W. The Intertropical Convergence Zone continues from 02N21W to 00N49W. Scattered moderate to isolated strong convection prevails along and within 150 nm on either side of the Monsoon Trough between 12W-22W. ...DISCUSSION... ...GULF OF MEXICO... A 1023 mb high is centered over the west Atlantic near 29N67W with a surface ridge extending across northern Florida to the northern Gulf of Mexico along 29N. A 1019 mb surface high was analyzed over the Florida Panhandle near 30N84W. With this, a gentle to moderate anticyclonic flow prevails across the basin, with strongest winds over the Straits of Florida and the southeast Gulf south of 26N east of 86W. Latest radar imagery depicts scattered moderate convection developing along the eastern coast of Mexico reaching portions of southern Texas. This activity could move offshore through the night, affecting the northwestern Gulf waters west of 94W. The nocturnal thermal trough that develops every night is once again over the Bay of Campeche, extending from 22N91W to 19N93W. Little change in marine conditions is expected during the next 24-48 hours, with a nocturnal surge of moderate to fresh winds expected west of the Yucatan Peninsula in the overnight hours. The surface high will remain over land during the next 24 hours. CARIBBEAN SEA... Gentle to moderate trades prevail across the basin, except pulsing moderate to fresh northeast winds off the coast of Colombia and across the approach to the Windward Passage. Scattered moderate convection is weakening over western Colombia to across Panama and southern Costa Rica. In the upper levels, a trough extends its axis roughly along 80W. With this, cloudiness and scattered convection prevails east of the trough over portions of eastern Hispaniola and Puerto Rico, as well as their adjacent waters. Expect little change over the next 24-48 hours. ...HISPANIOLA... Scattered showers are moving across the eastern portion of the island supported by an upper-level trough to the west, and with upper-level diffluence which has been over the island. This activity should diminish towards the morning, but similar conditions are possible this afternoon/evening. ATLANTIC OCEAN... A 1023 mb high is centered over the W Atlantic near 29N67W. To the east, a gale-force low is centered to the north of the area supporting near-gale wind north of 26N between 43W-53W. Seas in this area are ranging between 15-22 ft. Its associated dissipating cold front has transitioned into a surface trough extending from 31N34W to 19N40W. Another surface trough extends from 15N54W to 15N61W. No significant convection is related to these features at this time. The gale-force low is forecast to move southeast during the next 24 hours, reaching 31N42W by this afternoon. Expect for the surface troughs to dissipate by that time. Little change is expected elsewhere. For additional information please visit http://www.hurricanes.gov/marine $$ ERA