000 WTNT44 KNHC 280234 TCDAT4 Tropical Storm Harvey Discussion Number 31 NWS National Hurricane Center Miami FL AL092017 1000 PM CDT Sun Aug 27 2017 The unprecedented flooding rainfall event continues to unfold over much of southeastern Texas. Harvey has been moving slowly east- southeastward during the past few hours, and heavy rainbands continue to form over the northwestern Gulf and train inland over much of the upper Texas coast and southwestern Louisiana. Storm total rainfall amounts in the 20-27 inch range have been observed across much of the Greater Houston area, and additional rainfall amounts of 15 to 25 inches are expected over the next several days. Rainfall totals could reach 50 inches in some locations, which would be historic for that area. There haven't been any observations of sustained 34-kt winds over land for the past few hours, but the initial intensity remains 35 kt based on the assumption that higher winds are occuring over water, likely in rainbands. The track guidance continues to show Harvey moving just offshore of the Texas coast on Monday, then turning northward and moving inland over northeastern Texas in 48 to 72 hours. All of the global models show some slight deepening of the system after it moves over water, but given the lack of an inner core, significant strengthening is not anticipated. The new NHC track and intensity forecasts are similar to those from the previous advisory. Although the tropical storm warning has been expanded, and may need to be extended eastward along the upper Texas and southwest Louisiana coasts tomorrow morning, heavy rainfall and life- threatening flooding continue to be the primary threats. Key Messages: 1. Ongoing catastrophic and life-threatening flooding will continue across southeastern Texas. Additional rainfall accumulations of 15 to 25 inches are expected across the upper Texas coast, with isolated storm totals as high as 50 inches. 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 is spreading farther east into Louisiana. Additional rainfall amounts of 15 to 25 inches are expected in southwestern Louisiana, with rainfall amounts of 5 to 15 inches expected in south-central Louisiana. 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 28/0300Z 28.8N 96.6W 35 KT 40 MPH...INLAND 12H 28/1200Z 28.6N 96.4W 35 KT 40 MPH...NEAR THE COAST 24H 29/0000Z 28.3N 96.0W 40 KT 45 MPH...OVER WATER 36H 29/1200Z 28.4N 95.7W 40 KT 45 MPH...OVER WATER 48H 30/0000Z 28.8N 95.3W 40 KT 45 MPH...OVER WATER 72H 31/0000Z 30.5N 94.8W 35 KT 40 MPH...INLAND 96H 01/0000Z 32.3N 93.9W 30 KT 35 MPH...INLAND 120H 02/0000Z 34.0N 92.5W 25 KT 30 MPH...INLAND $$ Forecaster Brennan