The environment feeding this prolific "quad-state" tornadic storm is fairly close to the upper bound of the observed tornado parameter space. 50+ kt of 0-1 km BWD, plus 300+ 0-500 SRH. 70-80 kt 0-6 km BWD. pic.twitter.com/NMJQ7MkA0i

— John Peters (@UpdraftwMax) December 11, 2021