Confirmed tornadoes were reported in Illinois and Iowa Wednesday night as severe weather brought the risk of thunderstorms and prompted a flurry of tornado warnings for a large swath of the Midwest.

According to the National Weather Service, a confirmed tornado was reported near the small northeast Iowa community of Harpers Ferry at 5:10 p.m., while a second confirmed tornado rolled through Charleston in central Illinois at about 6:40 p.m. local time.

Both tornadoes were flagged by the weather service as a "particularly dangerous situation," a rare designation used by the weather service for environments in which "strong and violent tornadoes" are possible.

Photos and videos obtained by CBS News showed extensive damage in Charleston, with downed trees and power lines. Hail that measured 2.75 inches was also reported in the Charleston area, according to the weather service.

"There are a large number of trees blocking roadways throughout Charleston at this time," Charleston police said in a Facebook post. "Unless it is an absolute emergency, do not drive or attempt to go anywhere."

The city of Charleston later declared a local state of emergency. 

One cell phone video captured the terrifying moments what appeared to be a large tornado tore through Effingham, Illinois, which is located about 40 miles southwest of Charleston.

Larry Thies, coordinator for the Effingham Emergency Management Agency, told CBS News that initial information indicated damaged buildings, trailers, and downed power lines and trees. He said officials were working to set up an emergency operations center, but were facing challenges because internet was down in the area.

The extent of the damage to region was still unclear. There was no immediate word of injuries or fatalities. CBS News senior meteorologist Rob Marciano said there were at least seven reported tornadoes during the weather event.

According to utility tracker PowerOutage.us, at least 55,000 customers were without power in Illinois.

Earlier Wednesday, Marciano reported that 125 million Americans were facing severe weather advisories, including the Gulf Coast states, which were under flood alerts due to Tropical Storm Arthur. Speaking on "CBS Evening News," Marciano said such ripe tornado conditions were rare for June.

"This is unique for June, this is unusual to have such a strong jet stream just screaming across the country, then you've got the summertime tropical moisture coming in…and then some cold air coming in," Marciano said. "And winds coming at different direction, at different levels, creating that spin. So what that equates to is really the high probability of seeing, not just tornadoes, but intense tornadoes of EF2 strength or higher on the ground for a long time. And also damaging winds at 75 mph or higher, and of course big time hail."