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#897005 (Received by flhurricane at: 10:41 AM 31.Jul.2017) TCDAT1 Tropical Storm Emily Discussion Number 3 NWS National Hurricane Center Miami FL AL062017 1100 AM EDT Mon Jul 31 2017 There has been little change in Emily`s overall structure as seen in satellite and radar imagery over the past several hours. The inner-core convection has waxed and waned while the outer convective bands and rain shield on the south side of the small cyclone have remained fairly steady. Velocity data from the NOAA Tampa Bay WSR-88D Doppler radar has been indicating average velocities of 50-52 kt, with isolated bins of 55-62 kt, just south of the circulation center between 4000-5000 ft altitude during the past few hours. Using a standard adjustment factor of 80 percent still supports a surface wind speed estimate of 40 kt. Little change in strength is forecast until landfall occurs, after which slow weakening is expected as Emily moves across the Florida peninsula through tonight. After emerging off of the east-central Florida on Tuesday, some slow re- strengthening is forecast on days 2-3 when Emily will be moving over SSTs of 28C and the vertical wind shear will shift from northwesterly to southwesterly and decrease to 10-15 kt. By 96 h, the shear is forecast to increase to 25-30 kt, which should keep the intensity steady or induce slight weakening until Emily dissipates in about 120 h. Since Emily is not expected to regain tropical storm status before it moves offshore of the Florida east coast Tuesday morning, no watches or warnings are required for that area. The initial motion estimate is 090/08 kt. Emily is approaching the mouth of Tampa Bay, and landfall along the west-central Florida coast should occur by early afternoon. After landfall, the latest model guidance remains in excellent agreement on Emily turning east-northeastward tonight and moving across the central Florida peninsula as a depression, and emerging off of the east-central Florida coast Tuesday morning. A mid-/upper-level trough currently located over the upper Midwest is forecast to dig southeastward and amplify along the southeastern U.S. coast by 24-36 h, accelerating Emily to the northeast over the open Atlantic through the remainder of the forecast period. The new NHC forecast track is just an update and extension of the previous advisory track, and lies close to the TVCN consensus model. The primary threat with Emily is expected to be locally heavy rainfall across central an southern portions of the Florida peninsula during the next day or two. However, a brief tornado will be possible across central and southern Florida today, along with isolated waterspouts over the coastal waters of southwestern Florida. FORECAST POSITIONS AND MAX WINDS INIT 31/1500Z 27.6N 82.8W 40 KT 45 MPH 12H 01/0000Z 27.7N 81.6W 30 KT 35 MPH...INLAND 24H 01/1200Z 28.9N 79.6W 35 KT 40 MPH...OVER WATER 36H 02/0000Z 30.5N 77.7W 35 KT 40 MPH 48H 02/1200Z 32.2N 75.6W 40 KT 45 MPH 72H 03/1200Z 35.3N 70.8W 40 KT 45 MPH 96H 04/1200Z 37.7N 63.5W 40 KT 45 MPH 120H 05/1200Z...DISSIPATED $$ Forecaster Stewart |