Usually by this point in the season we've stopped talking about all the reasons why storms may struggle to become and remain severe. But (as someone else said) "because 2017" -- once again a storm setup may be totally trashed by morning thunderstorms in the warm sector. But then again, maybe not.
This is a setup we've been watching for the past 4-5 days, with models in general agreement that somewhere in the plains will have severe weather on Wednesday. The other thing most models paint at this point is precipitation in central and southern Oklahoma through early afternoon, which would tap the moisture coming in from the Gulf and leave the atmosphere worked over. But all that can be rectified with a few hours of midday heating, and there are enough indications that SPC has continued their 15% risk area for Wednesday.