Cyclic supercell with a well-defined hook now approaching the southwest side of Oklahoma City. Right now, it looks like the meso will cross I-44 in the next 20 minutes and enter the west side of Moore.

UPDATE: Tornado on the ground in southern Moore, OK.

UPDATE: Tornado now moving east along I-240 near Valley Brook, approaching Tinker AFB. Radar shows a reflectivity ball at the tip of the hook, indicative of a a debris cloud.

UPDATE: Extensive damage in Moore and SE Oklahoma City. Tornado still on the ground near Choctaw, approaching Harrah.