In Chicago, 29 possible tornado paths are being investigated, dating back to storms that later moved into Michigan.

On Monday evening, severe storms swept through the Great Lakes region, causing widespread damage through wind and tornadoes in several states. Chicago was hit particularly hard, with a tornado warning in effect for the entire city at times. The storms then moved east and hit southern parts of Michigan.

After the storms pass, the National Weather Service (NWS) in Chicago announced it will send out six survey teams to examine the 29 possible damage paths and determine how many of these areas may have been caused by tornadoes.

By late Tuesday afternoon, the NWS Chicago confirmed that six low-intensity tornadoes had touched down during Monday’s storm.

Trained meteorologists examine various damage indicators to determine if a tornado or straight-line winds were the cause. Monday evening, there were several circulations embedded in a large arc segment, with incredibly strong winds both within the circulations and where there were also purely straight-line winds.

At one point, the NWS in Chicago had to seek shelter from a possible tornado heading toward the company on Monday evening and hand over operations to the NWS in Gaylord, Michigan, until the danger passed.

This complex storm front moved eastward and affected southern Michigan, including Jackson, Kalamazoo, and Battle Creek. Several severe weather advisories with a tornado possible warning were issued for these areas, but no tornado warnings.

Fortunately, the worst of this system remained in the south of the state.