Part of a larger severe weather event that impacted the Central United States, the tornado first touched down in Lee County at 6:39 p.m. CDT (23:39 UTC).

Along the tornado's 30.14-mile (48.51 km) path, numerous structures were heavily damaged or destroyed, especially in the small town of Fairdale where two fatalities and eleven injuries were recorded.

No further changes to the threat level were made, although the Enhanced risk was significantly expanded late on April 8 to include portions of the southern Great Lakes, lower Ohio Valley, Ozark Plateau, and Ark-La-Tex region.

A weaker disturbance pushed from the Ozarks into the Northeastern United States, acting to strengthen southwesterly winds aloft across the risk area.

At the surface, a weak area of low pressure initially centered over northeastern Kansas early on April 9 progressed steadily northeast while intensifying, reaching the trisection of Iowa, Wisconsin, and Illinois by late that evening.

Modest surface heating ahead of the cold front allowed mid-level Convective Available Potential Energy (CAPE) values to reach 1,000–1,500 J/kg, and a mass of rich moisture transported northward from the Gulf of Mexico pushed dewpoints into the lower 60s °F across the Enhanced risk area.

[6] At 1:50 p.m. CDT (18:50 UTC), the SPC issued a tornado watch for northern and central Illinois, far northwestern Indiana, far southern Wisconsin, and portions of Lake Michigan.

[8] Isolated shower activity began forming across the region just prior to the issuance of watch,[9] eventually growing into a line of strong to severe thunderstorms, including supercells.

Intensifying to EF3 strength, much more severe damage was noted along South Skare Court as the tornado entered an area of semi-rural subdivisions to the northwest of Rochelle.

[14] As the tornado crossed South Richard Road, it intensified to very high-end EF4 strength and inflicted catastrophic damage to several large homes as it impacted the Deer Creek subdivision.

Continuing northeast, the tornado temporarily weakened, producing EF2 to EF3 damage as it destroyed a few large barns or outbuildings, ripped the roof off two brick residences, and collapsed most walls of another house, but once again gained strength as it approached and crossed IL 64.

Intense ground scouring was evident nearby, a car was thrown a full mile (1.6 km), and debris was wind-rowed long distances through fields in this area.

After passing over rural terrain, the tornado finally dissipated at 7:20 p.m. CDT (00:20 UTC) over Cherry Valley Road, ending its 30.14 mi (48.51 km) and 41-minute path of destruction.

The footage which captured the tornado's approach and destruction of several houses (including the homes of Klosa and the Schultzes) was recovered and was released online and in news broadcasts as a cautionary example.

[20] More than 675 volunteers, coordinated by the Virginia faith-based nonprofit organization Operation Blessing, and countless residents from surrounding areas assisted in cleanup efforts.

[27] Governor Bruce Rauner declared DeKalb and Ogle counties as state disaster areas, freeing up a wide variety of resources for response efforts.