000 WTNT44 KNHC 300254 TCDAT4 Tropical Storm Harvey Discussion Number 39 NWS National Hurricane Center Miami FL AL092017 1000 PM CDT Tue Aug 29 2017 Latest radar imagery shows that heavy rainfall continues over far eastern Texas and southwestern Louisiana. Outer bands are also producing heavy rain farther east along portions of the northern Gulf coast. However, rains have begun to diminish over the Greater Houston area, where some locations have received more than 50 inches during this historic event. Harvey took an eastward jog this evening, but recent satellite images suggest that a northeastward motion has resumed. The storm is expected to move north-northeastward to northeastward between a ridge over the eastern Gulf of Mexico and a trough over the east-central United States. This motion should bring the center onshore over southwestern Louisiana early Wednesday, and into the Tennessee Valley region later this week. The global models show the system becoming an open trough near the Ohio Valley or Appalachians in 4 to 5 days. The latest NHC track forecast has been shifted eastward partially due to the more eastward initial position. There has been little overall change to Harvey's convective structure since the previous advisory, and the initial intensity remains 45 kt, which was supported by the earlier aircraft data. Little change in strength is anticipate before Harvey reaches the Louisiana coast. After that time, gradual weakening should occur while Harvey moves farther inland. The latest forecast required an extension of the tropical storm warning eastward to Grand Isle, Louisiana. Key Messages: 1. Ongoing catastrophic and life-threatening flooding will continue across southeastern Texas. Additional rainfall accumulations of 6 to 12 inches are expected to the north and east of Houston from far east Texas into southwestern Louisiana. Isolated storm totals have reached 50 inches over the upper Texas coast, including the Houston/Galveston metropolitan area. Please heed the advice of local officials. Do not attempt to travel if you are in a safe place, and do not drive into flooded roadways. Refer to products from your local National Weather Service office and the NOAA Weather Prediction Center for more information on the flooding hazard. A summary of rainfall totals compiled by the Weather Prediction Center can be found at: www.wpc.ncep.noaa.gov/discussions/nfdscc1.html 2. The flood threat has spread farther east, and additional rainfall amounts of 5 to 10 inches are expected in southern Louisiana into coastal Mississippi and Alabama. These rains will spread north by mid to late week, with rainfall amounts of 4 to 8 inches in portions of Arkansas and the Tennessee Valley. Please heed the advice of local officials and refer to products from your local National Weather Service office and the NOAA Weather Prediction Center for more information on the flooding hazard in these areas. FORECAST POSITIONS AND MAX WINDS INIT 30/0300Z 29.0N 93.6W 45 KT 50 MPH 12H 30/1200Z 29.8N 93.0W 40 KT 45 MPH...INLAND 24H 31/0000Z 31.1N 92.3W 30 KT 35 MPH...INLAND 36H 31/1200Z 32.5N 91.2W 30 KT 35 MPH...INLAND 48H 01/0000Z 34.3N 89.5W 25 KT 30 MPH...INLAND 72H 02/0000Z 36.8N 85.9W 25 KT 30 MPH...POST-TROP/INLAND 96H 03/0000Z 39.0N 81.5W 20 KT 25 MPH...POST-TROP/INLAND 120H 04/0000Z...DISSIPATED $$ Forecaster Brown