000 AXNT20 KNHC 312346 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 746 PM EDT Thu Aug 31 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 1800 UTC surface analysis and satellite imagery through 2315 UTC. ...SPECIAL FEATURES... Hurricane Irma is centered near 17.3N 34.8W at 31/2100 UTC or about 617 nm west of the Cabo Verde Islands, moving west- northwest at 10 kt. Estimated minimum central pressure is 967 mb. Maximum sustained wind speed is 100 kt with gusts to 120 kt. Scattered moderate to isolated strong convection is from 14N-19N between 32W-38W. Irma is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. See the latest Intermediate Public Advisory under AWIPS/WMO headers MIATCPAT1/WTNT31 KNHC and the full Forecast/Advisory under AWIPS/WMO headers MIATCMAT1/WTNT21 KNHC for more details. ...TROPICAL WAVES... A tropical wave over the central Atlantic extends from 22N53W to 09N53W, moving west at 15 kt. The wave coincides with an amplified 700 mb trough in model wind fields. The SSMI TPW satellite imagery shows an area of modest deep layer moisture. Satellite imagery also shows an area of Saharan dust to the west of the wave. No convection is observed within this wave at this time. A tropical wave over the central Caribbean extends from 22N80W to 08N81W, moving west at 15 kt. The wave coincides with modest 700 mb troughing in model wind fields, and with curvature of low- level winds in scatterometer data. SSMI TPW imagery shows this wave is embedded in an area of modest deep layer moisture. Scattered moderate to isolated strong convection is over E Cuba and Jamaica. Scattered moderate to isolated strong convection is over the SW Caribbean, Honduras,and Nicaragua from 10N- 17N between 81W- 88W. A tropical wave over the Bay of Campeche extends from 22N94W to 09N95W, moving west at 15-20 kt. The wave coincides with subtle 700 mb troughing in initial model wind fields. SSMI TPW satellite imagery shows this wave is embedded in an area of modest deep layer moisture. Scattered moderate to isolated strong convection is inland over the Yucatan Peninsula and S Mexico. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from 13N17W to 14N26W then resumes from 13N37W to 10N52W. The ITCZ is from 10N52W to 10N61W. Scattered moderate isolated strong convection is off the coast of W Africa from 06N-15N between 20W-24W. Similar convection is from 10N-14N between 37W-43W. ...DISCUSSION... GULF OF MEXICO... Tropical Depression Harvey is centered over N Mississippi, moving NE at 17 kt and weakening. Further S, a surface trough is over the N Gulf of Mexico from 30N88W to 26N93W. Isolated moderate convection is within 120 nm E of the trough axis over the NE Gulf and the Florida Panhandle. Scattered moderate convection is also over the Florida Peninsula, and W Cuba. A tropical wave is over the Bay of Campeche. See above. In the upper levels, an upper level trough is over the NW Gulf and Texas with strong subsidence. The remainder of the Gulf has a large amount of upper level moisture. Expect the upper level trough to move E over the next 24 hours. CARIBBEAN SEA... A tropical wave is over the central Caribbean. See above. Further S, the eastern portion of the E Pacific monsoon trough passes over the SW Caribbean along 10N with scattered showers. Recently, widely scattered moderate convection has developed over Hispaniola, the central Caribbean, N Venezuela, and N Colombia. Satellite derived wind data depicts moderate to fresh trades covering the basin. An upper level low is centered over the SW Caribbean near 13N79W. Expect additional convection over the W Caribbean over the next 24 hours. ...HISPANIOLA... Presently widely scattered moderate convection is over the island. Expect a dry weather pattern to prevail across the island during the next couple of days. ATLANTIC OCEAN... Hurricane Irma is over the eastern Atlantic, and a tropical wave is is over the central Atlantic. Please see above. A frontal boundary extends across the W Atlantic, analyzed as a cold front from 30N55W to 27N64W, then as a stationary front from that point to 27N70W to 30N80W. Scattered showers and thunderstorms are observed along the cold front. A 1019 mb surface high is centered N of the front near 33N73W. A surface trough extend from 28N47W to 24N50W. Isolated moderate convection is within 90 nm of the trough. The remainder of the basin is dominated by a 1027 mb high centered over the Azores near 38N27W. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa