We left Oklahoma City where we were staying to head for Colorado for a short break in the Rocky Mountains. On reaching extreme south eastern Colorado we checked the National Weather Service radar which is displayed online, only to find a supercell rapidly forming in south western Kansas. Although chasing this storm would mean a 200 mile detour to our already 8 hour drive we decided to chase! After driving for three further hours we reached the storm at sunset which lit up some amazing Mammatus. Now deep under the cloud we watched the lightning display crawling across the sky until the storm began to decay when we decided to continue our drive on to central Colorado, where we arrived at our hotel at 4:10am after 901 miles!