Well, looking at the latest 00Z NAM... I'm thinking there is a decent threat for severe weather across IA. Instability looks pretty good with CAPE >2000J/KG in the warm sector, also of interest are the 0-3km helicities in excess of 350m2/s2 over a rather large area overlapping instability... So, if the NAM turns out to be right, I wouldn't doubt supercells and bow echos in the least bit (bow echo and HP supercell environments overlap like this quite a bit). The NAM shows a rather breakable cap, with precip breaking out by mid-afternoon... So, assuming we get sufficiant convergance along the surface front (which we should) and storms are able to become SFC-based - then, I would say supercells with large hail and PERHAPS an isolated tornado or two are possible.