Tornadoes are rated on the Enhanced Fujita (EF) Scale based on estimated 3-second wind gusts in miles per hour (mph). An EF0 tornado, the weakest category, has winds from 65 to 85 mph. To assess the impact on small UAS performance, which are typically limited to winds around 20 knots (kt), convert the minimum EF0 wind speed of 65 mph to knots using the approximation 1 kt = 1.15 mph. The converted speed is approximately

Refer to the provided figure. According to the 24 HR SIG WX PROG LOW LVL chart (VT 06Z Sun Apr 15 2012), the area depicted with extreme turbulence symbols presents the greatest risk to small UAS performance from