Ameren Missouri said on its website Monday most of those without power should be restored by the end of the day. Nearly all of the outages were reported inside St. Louis County.
The utility company says it restored service to another roughly 7,000 customers Sunday night into Monday. About 175 of the 400 power poles broken by the storms have been replaced.
In a preliminary damage survey posted on its website, the NWS reports the tornado only caused two minor injuries, but damaged dozens of homes and buildings after it touched down at 7:50 p.m. CDT.
Among the damage was a building that lost most of its roof at Hollywood Casino.
Hardest hit was a street in St. Charles, not far from where the tornado first touched down. Haversham Drive saw three homes with only interior walls remaining after the tornado, with several other homes sustaining damage on the block. Wind speeds topped out at an estimated 150 miles per hour there.
The tornado formed four miles southwest of Weldon Spring in southern St. Charles County, moving through Harvester, Earth City, Bridgeton, Ferguson, Bellefontaine Neighbors and ending on the edge of St. Louis city limits.
The tornado stayed on the ground for approximately 35 minutes, moving 32.5 miles from start to finish, according to the NWS damage survey.