It's such a big shift that I'm inclined to believe it's not only an outlier in terms of its own ensemble, but also probably unrealistic.
One thing I've noticed is that the new deterministic GFS really struggles with cutting off lows too quickly. Today's 18z operational does that exact same thing. It reminds me of a more subtle form of the same bias that the CMC struggles with.
One big red flag for this extreme warm solution is that the GFS's AI counterpart was much more troughy, following its previous solutions to a tee; in fact taking an opposite move toward even deeper troughing.
I was watching the radar and it looked like a sure thing you'd get clobbered, but once again all of those storms were mostly diverting just north and south of Ottumwa. It's likely areas north of you will be hit by a strong line Thursday morning, but Ottumwa and points south might get missed.