000 AXNT20 KNHC 101739 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 139 PM EDT Thu May 10 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 1200 UTC surface analysis and satellite imagery through 1730 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough meanders westward across tropical western Africa, exits along the coast of Guinea-Bissau near 10N14W, and extends south-southwestward to near 03N20W. The ITCZ continues west-southwestward 03N20W to 01N30W, and then extends westward to 01N50W along the coast of northern Brazil. WIdely scattered to scattered moderate convection is occurring within 150 nm either side of the ITCZ, and within 150 nm along and south of the monsoon trough. ...DISCUSSION GULF OF MEXICO... A 1021-mb High was located over north Florida, with a broad ridge extending westward along the Gulf coast to eastern Texas. Winds are southeasterly at 10 to 15 kt west of 92W, with generally easterly of 10 kt east of 92W. Weakening showers and isolated thunderstorms were occurring over the extreme southeastern Gulf of Mexico west of the Lower Keys. A weak surface trough with no shower activity was located over the eastern Bay of Campeche. The ridge will persist from the western Atlantic across the northern Gulf into early next week. A weak trough will form over the Yucatan Peninsula during the evening, move offshore the Peninsula to over the eastern Bay of Campeche overnight through the morning, then dissipate in the afternoon through the weekend. CARIBBEAN SEA... An elongated trough extended from near the Isle of Youth southward to 16N83W, and continuing sewd to near San Andres Island and to a weak surface low pressure system located near 10N77W. Scattered showers and isolated thunderstorms are occurring along and within 60 nm of the trough from Cuba southward to 20N. South of 20N, a narrow line of broken moderate showers was present along the trough axis to near San Andres. A small cluster of moderate to strong thunderstorms was occurring within 120 nm west-north-east of the low. Elsewhere east of 80W, mostly fair weather with only isolated light showers were occurring. Moderate to fresh trade winds are observed east of the trough axis with mostly 4 to 6 ft seas, and generally light northerly flow west of the trough with 2 to 4 ft seas. In the tropical Atlantic west of 55W, seas are still reaching 8 ft as noted in various altimeter satellite passes, largely due to fresh trades and lingering NE to E swell. The trough over the western Caribbean will drift westward through late today before before moving inland across Central America on Friday, and dissipating by Saturday. Moderate to fresh trades will persist east of the trough, with pulses of fresh to strong trade winds off northeast Colombia mainly at night. Seas east of Windward Islands will subside below 8 ft late today. ATLANTIC OCEAN... A surface trough, the remnants of an old frontal boundary, extends from 31N77W southwestward to the central Bahamas and continuing to west-central Cuba near 23N80W. A narrow band of moderate to strong showers and isolated thunderstorms were occurring along the trough over the Straits of Florida west of 80W. Isolated moderate showers were occurring over much of the central Bahamas. Generally SE flow of 10 kt was noted SE of the trough to 60W, becoming easterly E of 60W. West of the trough, winds were generally N at 10 kt. Elsewhere east of 60W, the eastern Atlantic is dominated by a large 1029-mb subtropical High. Seas were 5 to 7 ft in open waters east of the Bahamas, and 3 to 5 ft north of the Bahamas and off the coast of northeast Florida. The trough will meander and weaken through today before drifting slowly northwest Friday and Saturday. A ridge will build from the central Atlantic southwestward across the waters north of 25N through Friday, producing generally moderate to fresh winds south of 22N east of the Bahamas, but with pulses of fresh to strong winds off the north coast of Hispaniola mainly at night through late Sunday. The moderate pressure gradient equatorward of the high is producing tradewinds of 10 to 15 kt N of 20N and 15 to 20 kt S of 20N. The winds N of 20N support seas of 5 to 7 ft, while the winds S of 20N support seas of 6 to 8 ft. No major changes are expected in the pattern across the central and eastern subtropical and tropical Atlantic over the next few days. For additional information please visit http://www.hurricanes.gov/marine $$ Stewart