The beige area running east to west shows the path of EF-5 tornado that devastated central Oklahoma on May 20, 2013. According to the National Weather Service, the tornado was on the ground for 39 minutes, ripping across 17 miles. At its peak, the funnel cloud was 1.3 miles wide and wind speeds reached 210 miles per hour.
For size comparison: Manhattan, New York is 13.4 miles long and 2.3 miles at its widest point.
Larger views and more details about the image, including information about the color enhancement, can be found on NASA's website.