The Historic Cumberland Plateau Ice Storm of 20-21 February 2015

An historic ice storm struck Middle Tennessee on 20-21 February 2015 as part of an unprecedented period during which frequent winter storms affected the Tennessee Valley. Although effects of the ice storm were seen throughout Middle Tennessee, the most severe impacts occurred on the Cumberland Plateau; a region of elevated terrain in eastern Middle Tennessee ranging from 457 m (1,500 ft) to 1067 m (3,500 ft) above mean sea level. Ice accretions in this area were measured near and over 2.54 cm (1.00 in), which combined with strong winds up to 22 ms-1 (50 mph) caused massive damage to trees, electrical infrastructure, homes, businesses, and other structures. In the aftermath of the ice storm, 35,000 residents lost power, with some residents without electrical services for up to one month. Local emergency management described this ice storm as the "worst natural disaster in the history of this area, equivalent to EF2 tornado damage countywide,” with damage totals estimated in the tens of millions of dollars.

This case study will analyze this high-impact winter storm by reviewing the synoptic and mesoscale conditions, observed conditions, as well as forecasts leading up to the event. In addition, any influences the higher terrain may have had on worsening the ice storm impacts and damage will be examined. Finally, this study will discuss preparation efforts by local communities and emergency management based on NWS forecasts, as well as how real-time social media reports benefitted NWS warning operations during this historic ice storm.