Quick graphic with the position of the 15 Dec 2021 derecho. First and last severe/tornado warnings are noted. The derecho traveled roughly 660 miles in 10.5 hours, giving an average forward motion of 63 mph. That’s faster than some interstate speed limits in Iowa. pic.twitter.com/KsdFIIt8Ts

— Elizabeth Leitman (@WxLiz) December 16, 2021