Flood in Franklin County, Illinois

Heavy rainfall rates of around an inch in a 45 minute span resulted in large amounts of water ponding on roadways in Benton.

A surface cold front stalled out as it moved towards the northern edge of the Quad State on the 17th. Showers and thunderstorms developed during the afternoon hours, tracking eastward, including a broken line of storms moving through the Evansville Tri-State area mid-afternoon. An outflow boundary from a decayed MCS to the north helped initiate some of the storm development. MLCAPE was a very strong 4000J/kg but bulk shear was limited. Precipitable water values were a very high 2.2 inches. Despite an active weather day, the lack of shear kept severe weather potential limited, and the lack of training with the heavy rain kept flooding from becoming widespread. The lone report out of Southern Illinois was of ponding of roads in Benton from heavy rainfall rates.