Severe thunderstorms are possible this weekend in a swath generally extending from the northcentral High Plains, Southeastward across Nebraska, parts of Iowa and much of Missouri, into the western Tennessee and mid-Mississippi Valley areas.
Specifically, here is the outlook for today, Saturday, from the SPC:
...and for tomorrow, Sunday:
Severe thunderstorms are possible anywhere within the yellow shaded areas on the above images.
Damaging winds & large hail will be the primary threats, however isolated tornadoes also cannot be ruled out, particularly during the first couple of hours that storms initially develop, when they are isolated to scattered in coverage. One or more complexes of thunderstorms are likely to form both Saturday Night and Sunday Night (from smaller scale activity that develops each afternoon & evening) and move East/ Southeastward during the overnight hours. Damaging straight-line winds would be the greatest threat from that portion of the activity.