000 AXNT20 KNHC 301723 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 123 PM EDT Wed Aug 30 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 1200 UTC surface analysis and satellite imagery through 1715 UTC. ...SPECIAL FEATURES... Tropical Storm Harvey is centered near 30.5N 93.3W at 30/1500 UTC or about 26 nm NNW of Lake Charles Louisiana, Texas moving NNE at 7 kt. Estimated minimum central pressure is 993 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Scattered moderate convection is observed north of 29N between 87W-95W. Catastrophic flooding is still expected over southeast Texas and southwest Louisiana. See the 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. As of 30/1500 UTC, the previously low pressure located within 300 nm west of the Cabo Verde Islands is now T.S. Irma. Irma is centered near 16.4N 30.3W, moving west at 11 kt. Estimated minimum central pressure is 1004 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Numerous moderate convection is found from 11N-19N between 28W-35W. A recent scatterometer pass indicated 30-40 kt winds within 360 nm in the north semicircle of the cyclonic circulation. 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 with an axis extending from 24N46W to 09N47W, moving west around 15 kt. The wave coincides with an amplified 700 mb trough in initial model wind fields. TPW satellite imagery shows an area of modest deep layer moisture located on the east side of the wave. Satellite imagery also shows an area of Saharan dust to the east and west of the wave. No convection is observed within this wave at this time. A tropical wave over the central Caribbean with axis extending from 22N72W to 09N74W, moving west at around 10 kt. The wave coincides with modest 700 mb troughing in initial model wind fields and curvature of low-level winds in scatterometer data. SSMI TPW imagery shows this wave is embedded in an area of modest deep layer moisture. This wave is triggering scattered showers and thunderstorms south of 18N between 71W-80W. A tropical wave over the west Caribbean with axis that extends from 21N86W to 09N86W, moving west at 10 to 15 kt. The wave coincides with subtle 700 mb troughing in initial model wind fields. TPW satellite imagery shows this wave is embedded in an area of modest deep layer moisture. This wave is producing isolated showers from 17N-22N between 85W-88W. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from 20N16W to 16N30W to 09N50W. The ITCZ continues from 09N50W to 10N62W. Besides the convection associated with Irma, scattered moderate convection prevails within 100 nm north of the ITCZ affecting portions of the Windward Islands. ...DISCUSSION... GULF OF MEXICO... Tropical Storm Harvey is centered over southwest Louisiana near 30.5N93.3W. Please refer tot he section above for more details. To the east, a surface trough extends across the Florida Peninsula and adjacent waters from 30N86W to 30N83W to 30N79W. No convection is related to this feature at this time. An area of scattered showers has developed over the Bay of Campeche south of 23N and west of 93W. Harvey is expected to slowly weaken and reach northeast Louisiana by Thursday morning. Little change is expected across the remainder of the basin. CARIBBEAN SEA... Two tropical waves are moving across the Caribbean waters. See the Tropical Waves section above for additional details. The eastern portion of the E Pacific monsoon trough passes over the southwest Caribbean along 10N. Low-level convergence near the trough is producing scattered moderate and isolated strong convection along the coasts of Colombia and Panama south of 10N between 75W-80W. An area of scattered moderate convection is moving across the Windward Islands. This activity will continue moving west affecting the southeast Caribbean waters through the next 24 hours. Scatterometer data depicts moderate to fresh trades across the basin. ...HISPANIOLA... Isolated showers and thunderstorms are occurring over the island due to a passing tropical wave. Expect similar conditions during the next day or so until the wave moves farther west. ATLANTIC OCEAN... T.S. Irma has developed in the eastern Atlantic, while a tropical wave is moving over the central Atlantic. Refer to the sections above for details about these features. A surface trough extends from 31N43W to 26N44W with scattered moderate convection. The remainder of the basin is under the influence of a surface ridge anchored by a 1029 mb high centered near 38N27W and a 1019 mb high centered near 26N58W. For additional information please visit http://www.hurricanes.gov/marine $$ ERA