Tens of thousands are without power in sweltering heat after a spring storm hit the St. Louis region.

The St. Louis Post-Dispatch reports that a storm hit Thursday night, generating strong winds, heavy rain and, in places, hail. More than 40,000 Ameren customers in Illinois and 20,000 in Missouri were without power as of Friday morning. The outages come as highs are expected around the century mark.

A team from the National Weather Service will be surveying damage to see if any of it was caused by a tornado. Meteorologist Kevin Deitsch says the team will focus on the damaged marina area in Portage Des Sioux along the Mississippi River in St. Charles County, Missouri, where a truck flipped over. They'll also visit Spanish Lake, Missouri, and Granite City, Illinois.