Low-topped supercells will form in Northwest MO and Southwest IA this afternoon and move east-northeast throughout the evening, developing as far south as Columbia, MO. These storms will be in a low instability and high sheared environment. Due to the discreet nature of the system along with very high shear values … tornadoes (some strong) will be possible, centering along the IA/MO border or very close to it near or just south/southeast of the Creston, IA forecast region.
Storms will weaken below tornadic capabilities as they head eastward toward the Davenport, IA areas, the southern end into Western IL (Quincy) later in the period.
Strong upper divergence and a deformation band across Northern IA, Southeast/South MN and into North-Central WI. This band of heavy showers and thunderstorms will bring rainfall totals in the 1-3″ range in a short period of time, which will cause areas of flooding.