000 AXNT20 KNHC 260000 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 800 PM EDT Fri Aug 25 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 2345 UTC. ...SPECIAL FEATURES... Hurricane Harvey is now a category 4 hurricane centered near 27.8N 96.8W at 26/0000 UTC or about 30 nm E of Corpus Christi Texas, moving NW at 7 kt. Estimated minimum central pressure is 941 mb. Maximum sustained wind speed is 115 kt with gusts to 140 kt. Numerous moderate and scattered strong convection is present north of 26N and west of 90W. See latest Intermediate Public Advisory under AWIPS/WMO headers MIATCPAT4/WTNT34 KNHC and the full Forecast/Advisory under AWIPS/WMO headers MIATCMAT4/WTNT24 KNHC for more details. ...TROPICAL WAVES... A tropical wave extends its axis from 22N25W to a 1011 mb low near 18N27W to 12N29W, moving west at around 10-15 kt. The wave coincides with amplified 700 mb troughing. Infrared satellite imagery shows the presence of Saharan dust flanking the north side of the wave. No convection is observed with this wave at this time. A tropical wave extends its axis from 19N45W to a 1010 mb low near 15N43W to 10N40W, moving west at around 10-15 kt. Scattered moderate convection within 30 nm to the northwest of the low center. The wave coincides with amplified 700 mb troughing. The northern portion of a tropical wave extends across the far western Caribbean with axis along 88W. Global model guidance suggests subtle 700 mb troughing between 85W-90W moving over portions of Central America and the East Pacific waters. The convection associated to this wave remains over land affecting Yucatan Peninsula, Guatemala, Belize, and Honduras. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from 22N17W to 14N31W to 09N48W. The Intertropical Convergence Zone continues from 09N48W to 08N59W. No significant deep convection is associated with the monsoon trough or ITCZ at this time. ...DISCUSSION... GULF OF MEXICO... The primary weather threat for the Gulf of Mexico continues to be Hurricane Harvey which continues to track NW toward the southern Texas coast. Please refer to the section above for more details. To the east, a 1012 mb surface low is centered on the Florida coast close to Sarasota near 28N82W. A surface trough extends from 28N85W to the west Atlantic near 31N79W. Scattered moderate convection is mainly south of 29N and east of 87W affecting the southern portion of the Florida Peninsula and Straits, the Yucatan Channel, and even western Cuba. Scatterometer data depicts a variable gentle to moderate flow across the eastern half of the basin. As Harvey slows down and impacts the NW Gulf waters and coastal Texas through the upcoming weekend, the troughing and weaker low pressure across the eastern Gulf waters are expected to maintain unsettled conditions across the Florida peninsula before the low moves NE into the SW North Atlantic waters by late this weekend. CARIBBEAN SEA... Scattered to numerous showers and thunderstorms prevail across western Cuba and the adjacent waters supported by the low pressure system developing over the eastern Gulf of Mexico. Another area of scattered moderate convection prevails over the southwest Caribbean enhanced by the presence of the monsoon trough along 10N. Fair weather prevails elsewhere. Scatterometer data depicts gentle to moderate trades across the basin. This overall synoptic pattern is expected to persist through the weekend into Monday. ...HISPANIOLA... Isolated afternoon showers and thunderstorms are possible across central Hispaniola with maximum daytime heating and instability, along with local sea breeze effects. ATLANTIC OCEAN... Scattered moderate convection prevails across the western Atlantic west of 74W related to the surface low/trough that extend across this area from the Gulf of Mexico. Farther east across the remainder of the basin, ridging prevails anchored by a 1028 mb high centered near 41N40W. For additional information please visit http://www.hurricanes.gov/marine $$ ERA