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| #1057107 (Received by flhurricane at: 10:54 PM 15.Aug.2021) TCDAT1 Tropical Storm Fred Discussion Number 26 NWS National Hurricane Center Miami FL AL062021 1000 PM CDT Sun Aug 15 2021 Fred remains a sheared tropical cyclone however the overall organization of the system has improved somewhat since this afternoon. The low-level center is embedded near the western edge of the primary convective mass, and there has been an overall increase in deep convection near and to the east of the center. An Air Force Reserve reconnaissance aircraft that has been investigating Fred this evening has reported that the pressure has fallen to 999 mb and it has found winds to support an initial intensity of 45 kt. The plane found a very small area of slightly stronger flight-level and SFMR winds well east of the center, but those winds appear to have been associated with a strong convective cell and are likely not representative of the system`s overall intensity. Fred is moving north-northwestward or 330/08 kt, and this motion should continue overnight. The dynamical model guidance indicates that the tropical cyclone will turn northward on Monday as it approaches the coast of the Florida panhandle. A north- northeastward motion around the western periphery of a subtropical ridge over the western Atlantic should commence by the time the system makes landfall, and this general heading should continue until the system dissipates in a couple of days. The dynamical models envelope did not change much and the latest consensus aids were essentially along the previous NHC track. As a result, little alteration was made to the previous official track forecast. The cyclone is located within an area of moderate southwesterly vertical wind shear. However, most of the intensity guidance continues to suggest that Fred will strengthen a little over the next 12-18 hours. As the system nears the northern Gulf coast, the SHIPS guidance forecasts some increase in shear and the intensity models reflect this by showing a leveling off of Fred`s intensity at that time. After landfall, Fred should weaken quickly and dissipate over the Tennessee Valley in a little more than 48 hours. The updated NHC intensity forecast is in good agreement within the HCCA and IVCN consensus aids. Users are reminded not to focus on the exact forecast track of Fred, since rainfall, storm surge, and wind hazards will extend over an area well east of the center. KEY MESSAGES: 1. Through Tuesday, heavy rainfall may lead to flash, urban, small stream, and isolated river flooding impacts across the Southeast, including portions of southern Florida, the Big Bend and Panhandle of Florida, southeast Alabama, portions of Georgia, and the western Carolinas. By the middle of the week as Fred lifts north and inland toward the Tennessee Valley, heavy rainfall and flooding may impact the southern and central Appalachians, and the Piedmont of the Southeast and Mid-Atlantic. 2. Dangerous storm surge inundation is possible along portions of the coast of the Florida Panhandle and the Florida Big Bend region, and a Storm Surge Warning is in effect for this area. Interests in these areas should follow any advice given by local officials. 3. Tropical storm conditions are expected in the Tropical Storm Warning area in the Florida Panhandle beginning on Monday. FORECAST POSITIONS AND MAX WINDS INIT 16/0300Z 27.3N 85.9W 45 KT 50 MPH 12H 16/1200Z 28.6N 86.2W 50 KT 60 MPH 24H 17/0000Z 30.2N 86.1W 50 KT 60 MPH 36H 17/1200Z 32.3N 85.7W 30 KT 35 MPH...INLAND 48H 18/0000Z 34.4N 84.9W 20 KT 25 MPH...POST-TROP/INLAND 60H 18/1200Z...DISSIPATED $$ Forecaster Brown |