Here is one of the WRF models run at the University of llinois. This shows the CAPE values will be well over 4000 J/kg across southern Iowa and northern Missouri. There is also little if any capping layer in those areas according to this model thus thunderstorm development “should” not be impeded. However, this is only one model run (Another WRF model from UIUC showed similiar results at the same time), things can change including cloud cover, temperatures, possible boundaries off thunderstorms that may fire Friday night into Saturday morning south of the area. A lot of things will have to come together, but it’s looking more and more likely right now.