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| #900593 (Received by flhurricane at: 4:44 PM 29.Aug.2017) TCDAT4 Tropical Storm Harvey Discussion Number 38 NWS National Hurricane Center Miami FL AL092017 400 PM CDT Tue Aug 29 2017 Heavy rains continue to spread over southeastern Texas and southern Louisiana, exacerbating what is already a catastrophic flood event. Rainfall totals are around 50 inches at some isolated locations in the Greater Houston area and southeastern Texas. Convection blossomed a couple of hours ago, and the center jumped a little northward into the thunderstorm activity. Since that time, the center is back on track and is moving slower again toward the north-northeast at about 5 kt. Recent data from an Air Force Hurricane Hunter plane indicate that winds are about 45 kt, with a minimum pressure of around 994 mb. The SFMR on the plane reported some higher wind values but the plane was flying in shallow waters and these numbers appear inflated. Flight-level winds in the same area were much lower. Strong shear prevails over the cyclone, so no significant change in intensity is anticipated before the broad center of circulation makes landfall. A gradual weakening is forecast once the system moves inland. Harvey has been steered north-northeastward by a light southwesterly flow between a high in the Gulf of Mexico and a trough over the central United States. This flow pattern should keep Harvey on the same general track and speed with a gradual turn to the northeast in about 3 days. By then the cyclone is forecast to degenerate into a remnant low and then become absorbed by an extratropical low. Most of the guidance is consistent with this solution, and the NHC forecast is in the middle of the guidance envelope and very close to the multi-model consensus. Key Messages: 1. Ongoing catastrophic and life-threatening flooding will continue across southeastern Texas. Additional rainfall accumulations of 6 to 12 inches are expected across the upper Texas coast into southwestern Louisiana, 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 has spread farther east, and additional rainfall amounts of 5 to 10 inches are expected in southern Louisiana into coastal Mississippi and Alabama. 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 29/2100Z 29.2N 94.3W 45 KT 50 MPH 12H 30/0600Z 30.1N 93.7W 40 KT 45 MPH...INLAND 24H 30/1800Z 31.5N 93.0W 30 KT 35 MPH...INLAND 36H 31/0600Z 32.5N 92.5W 30 KT 35 MPH...INLAND 48H 31/1800Z 34.0N 91.0W 30 KT 35 MPH...INLAND 72H 01/1800Z 36.5N 88.0W 25 KT 30 MPH...POST-TROP/INLAND 96H 02/1800Z 37.5N 85.5W 25 KT 30 MPH...POST-TROP/INLAND 120H 03/1800Z...ABSORBED BY AN EXTRATROPICAL LOW $$ Forecaster Avila |
