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#899969 (Received by flhurricane at: 4:44 AM 27.Aug.2017) TCDAT4 Tropical Storm Harvey Discussion Number 28 NWS National Hurricane Center Miami FL AL092017 400 AM CDT Sun Aug 27 2017 Although the radar presentation of the inner core of Harvey has degraded considerably, the system continues to produce intense convection in bands to the east and southeast of the center. The current intensity estimate is set to 40 kt based on surface synoptic data over southeastern Texas. Since the center is expected to remain mainly over land during the forecast period, continued weakening is likely. Given that a significant portion of the circulation is over water, however, this weakening should be very slow to occur. The official intensity forecast is similar to the model consensus. Harvey has been meandering overnight and now appears to be drifting south-southwestward. The cyclone is trapped between mid-level highs to its west-northwest and east-southeast. Over the next couple of days, the flow on the southern periphery of a trough dropping over the east-central United States should cause Harvey to move slowly southeastward to eastward. Later in the forecast period, increased ridging to east of the cyclone should cause Harvey to turn northward. The official track forecast is close to the latest model consensus and brings the center to the coast and, briefly, just offshore of southeastern Texas. At this time, it is not expected that Harvey will move far enough out over the water to result in regeneration. The biggest concern with Harvey is now the rain, a lot of rain. Rainfall totals of nearly 20 inches have been reported in the Houston area. This is resulting in catastrophic flooding which, unfortunately, will continue for some time. Key Messages: 1. While Harvey's winds are decreasing, life-threatening hazards will continue from heavy rainfall over much of southeastern Texas and from storm surge along portions of the Texas coast. 2. Catastrophic and life-threatening flooding is expected across the middle and upper Texas coast from additional rainfall of 15 to 25 inches, with isolated storm totals as high as 40 inches, through Thursday. Please heed the advice of local officials 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 3. A Storm Surge Warning remains in effect for portions of the Texas coast. Life-threatening storm surge flooding will be slow to recede due to the slow motion of Harvey and a prolonged period of onshore flow. For a depiction of areas at risk, see the Storm Surge Watch/Warning Graphic at hurricanes.gov. FORECAST POSITIONS AND MAX WINDS INIT 27/0900Z 29.2N 97.7W 40 KT 45 MPH 12H 27/1800Z 29.0N 97.4W 35 KT 40 MPH...INLAND 24H 28/0600Z 28.7N 97.0W 30 KT 35 MPH...INLAND 36H 28/1800Z 28.5N 96.6W 30 KT 35 MPH...NEAR THE COAST 48H 29/0600Z 28.5N 96.1W 30 KT 35 MPH...INLAND 72H 30/0600Z 29.4N 95.6W 30 KT 35 MPH...INLAND 96H 31/0600Z 30.8N 95.5W 25 KT 30 MPH...INLAND 120H 01/0600Z 32.0N 95.0W 25 KT 30 MPH...INLAND $$ Forecaster Pasch |