000 AXNT20 KNHC 300606 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 206 AM 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 0000 UTC surface analysis and satellite imagery through 0500 UTC. ...SPECIAL FEATURES... Tropical Storm Harvey is centered near 29.2N 93.5W at 30/0600 UTC or about 40 nm SSW of Cameron Louisiana and 45 nm SSE of Port Arthur, Texas moving NE at 7 kt. Estimated minimum central pressure is 995 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Associated deep convection is displaced NNW of the center over the extreme NE Texas and extreme SW Louisiana coasts near the Sabine River. Feeder bands east of the center continue to produce isolated moderate convection over the north central Gulf N of 28N between 86W and 90W. Coastal areas of Louisiana, Mississippi, Alabama and the western Florida panhandle are also included in this area. 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. A tropical wave is over the E Atlantic associated with a 1008 mb low that is located near 16N27W. The wave axis extends from 23N25W to the low to 10N27W, moving W at 15-20 kt. Numerous moderate and scattered strong convection is found from 15N to 19N between 26W and 32W. Scattered moderate convection is occurring from 07N to 12N between 26W and 40W. A recent scatterometer pass indicated 20-25 KT winds within 180 nm in the N semicircle of the low. The wave is embedded in an area of deep layer moisture as seen on TPW satellite imagery. This system has become better organized since yesterday, and a tropical depression could form from this system over the eastern Atlantic during the next couple of days. Heavy rain is possible over portions of the northwestern Cabo Verde Islands for a few more hours. There is now a high chance for this system to become a tropical cyclone during the next 48 hours. ...TROPICAL WAVES... A tropical wave over the central Atlantic has an axis extending from 24N44W to 10N43W, moving W at 10-15 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 the presence of a large area of Saharan dust to the N and W of the wave. Scattered moderate and isolated strong convection is present from 08N to 10N between 40W and 45W. A tropical wave over the E Caribbean extends from 22N69W to 10N71W moving W at 15 to 20 kt. The wave coincides with modest 700 mb troughing in initial model wind fields and curvature of low- level winds in the most recent scatterometer pass. SSMI TPW imagery shows this wave is embedded in an area of modest deep layer moisture. This wave is triggering isolated thunderstorms over Hispaniola. A tropical wave over the W Caribbean extends from 21N84W to 09N83W, moving W at 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 thunderstorms along the east coast of Nicaragua. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from 18N16W to low pres 1008 mb centered near 16N27W to 10N50W. The ITCZ continues from 10N50W to 09N61W. Besides the convection associated with the tropical waves, scattered moderate convection is from 07N to 09N between 35W and 40W and from 11N to 13N between 56W and 61W, to include portions of the Windward Islands. ...DISCUSSION... GULF OF MEXICO... Tropical Storm Harvey has a low-level exposed center located over the Gulf of Mexico near 29N94W. Associated deep convection is displaced NNW of the center over the extreme NE Texas and extreme SW Louisiana coasts near the Sabine River. Feeder bands east of the center continue to produce isolated moderate convection over the north central Gulf N of 28N between 86W and 90W. Coastal areas of Louisiana, Mississippi, Alabama and the western Florida panhandle are also included in this area. Catastrophic inland flooding is forecast to continue over Texas and Louisiana during the next few days. Of interest, a preliminary report from a Texas rain gauge has broken the Texas tropical cyclone rainfall record. An upper-level trough extends southward through Oklahoma and Texas. Divergent upper level winds east of the trough axis are aiding convection over the Gulf of Mexico and Florida N of 26N. Harvey is expected to move slowly NE and move inland over SW Louisiana this morning and reach NE Louisiana Thursday morning. CARIBBEAN SEA... Two tropical waves are moving across the Caribbean waters. See the tropical waves section for additional details. The eastern portion of the E Pacific monsoon trough passes over Costa Rica and Panama. Low-level convergence near the trough is producing scattered moderate and isolated strong convection over Costa Rica and Panama. In the upper levels, an upper level low centered over the Yucatan Peninsula near 21N88W is enhancing showers over the Yucatan and Central America. ...HISPANIOLA... Isolated showers and thunderstorms are occurring over the island due to a tropical wave. Expect similar conditions during the next day or so until the wave moves farther west. ATLANTIC OCEAN... A broad 1028 mb high centered over the Azores near 39N27W ridges SW to another weaker 1020 mb high centered near 27N57W then to the southeastern Gulf of Mexico. Moderate to locally fresh trade winds prevail south of the ridge to the west of 30W. For additional information please visit http://www.hurricanes.gov/marine $$ McElroy