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#897043 (Received by flhurricane at: 4:53 PM 31.Jul.2017) TCDAT1 Tropical Depression Emily Discussion Number 4 NWS National Hurricane Center Miami FL AL062017 500 PM EDT Mon Jul 31 2017 Emily`s appearance in satellite and radar imagery has degraded significantly since the previous advisory, with only weak convection noted near the low-level center. The deepest convection is well removed from the center and lies across southern Florida and the Keys. Since Doppler velocity values at any altitude have decreased to less than 40 kt, the initial intensity has been lowered to 30 kt, resulting in Emily being downgraded to a depression on this advisory. The initial motion estimate is 070/10 kt. Emily made landfall on Anna Maria Island, Florida, around 1445Z. Since that time, the depression has been moving steadily eastward to east-northeastward, and this general motion is expected to continue through tonight. NHC model guidance remains in very good agreement on Emily emerging off the east-central Florida coast Tuesday morning, and then accelerating northeastward ahead of a digging mid-level trough and frontal system through the remainder of the forecast period. There is high confidence that Emily will not directly affect the southeastern United States after the small cyclone emerges over the Atlantic Ocean. The new NHC forecast track was nudged slightly to the east of the previous advisory track, and follows a blend of the TVCN and HCCA consensus models. Some additional weakening is possible tonight while Emily moves across the central Florida peninsula and entrains more dry air from the north and west of the system. However, once the compact cyclone emerges over the warm waters of the Gulf Stream in the Atlantic Ocean on Tuesday, some gradual re-strengthening is expected to begin while the vertical wind shear is modest at around 15 kt. By 48 h, the shear is forecast to increase to 20-30 kt, which should act to cap Emily`s intensity until the cyclone dissipates or merges with a frontal system in 96-120 h. Since Emily is not expected to regain tropical storm status when it exits the Florida east coast Tuesday morning, no watches or warnings are required for that area. The primary threat with Emily will continue to be locally heavy rainfall across portions of the southeastern Florida peninsula through tonight. FORECAST POSITIONS AND MAX WINDS INIT 31/2100Z 27.8N 81.7W 30 KT 35 MPH...INLAND 12H 01/0600Z 28.4N 80.2W 30 KT 35 MPH...OVER WATER 24H 01/1800Z 29.9N 78.2W 35 KT 40 MPH 36H 02/0600Z 31.4N 76.3W 40 KT 45 MPH 48H 02/1800Z 33.0N 74.0W 40 KT 45 MPH 72H 03/1800Z 35.6N 68.7W 40 KT 45 MPH 96H 04/1800Z 38.1N 61.5W 40 KT 45 MPH 120H 05/1800Z...DISSIPATED $$ Forecaster Stewart |