ST. LOUIS — Middle America was overwhelmed by weather Thursday, with snow in the north, tornadoes in the Plains, and torrential rains that caused floods and transportation woes — and a sinkhole in Chicago.

Seemingly every community in the Plains and Midwest was under some sort of watch or warning. Up to a foot of snow was expected in parts of Minnesota and the Dakotas. Snow and ice closed highways in Colorado. Rivers were surging beyond their banks from downpours in Missouri, Iowa and Illinois. Tornadoes caused scattered damage in Oklahoma. Frost warnings were in effect in Kansas and Oklahoma as a cold front pushed out warmer air.

“It’s a classic spring storm in many ways,” Mark Fuchs of the National Weather Service said. “There’s a wide variety of weather, a big temperature difference.”

Consider St. Louis. On Wednesday the temperature reached 85 degrees. Strong storms passed through on Thursday, and by Friday, the temperature is forecast to be around 40 degrees.

There were no immediate reports of deaths related to the vast array of foul weather around the country.

Chicago was pummeled by an all-night rainstorm that ripped open a sinkhole large enough to swallow three cars and injuring one driver badly enough that he had to be hospitalized. Police spokesman Mike Sullivan said the gaping hole opened up in a street on the city’s South Side, near Lake Michigan.

The injured man was driving when the road buckled and caved in. He was hospitalized with non-life threatening injuries. The other two cars were parked.

Flooding has also forced authorities to close sections of several major expressways around Chicago, canceled classes at some schools and scrapped around 550 flights at O’Hare International Airport. The gauge at O’Hare showed 5 inches of rain, and 2 more inches were expected Thursday.

Winds, possibly from a tornado, damaged dozens of homes in Spavinaw, Okla., injuring one person. Another twister damaged a few buildings near Paris, Mo. High winds also blew two tractor-trailers off a highway near Monroe City, Mo.

Up to a foot of new snow was expected in northern Minnesota. Duluth has already received 24 inches of snow this month, and the additional snowfall could push it past the April record of 31.6 inches set in 1950. Winter storm warnings were also posted for parts of North Dakota and South Dakota.

Snow and ice forced closure of sections of Interstate 70 and Interstate 25 in Colorado. The Wyoming Department of Transportation warned drivers to watch for black ice.

Flash flooding was reported in many places. In north-central Illinois, fire departments and rescue crews helped stranded motorists and residents. In Utica, the fire department evacuated a mobile home park. In Marshall County, boats were needed to rescue morning commuters trapped in flash flooding.

In Ava, Mo., a school bus carrying several children stopped because of water on the road. The driver turned around to go back, only to find flooding behind him, too. The driver and kids waited at a nearby home until help arrived. Outside the small town, an elderly couple was rescued from their mobile home after a fast-rising creek encircled the trailer.

“There were places around here this morning that like in 45 minutes got 3 inches of rain,” Douglas County Sheriff Chris Degase said.

Roads in Oklahoma, Iowa and Michigan were shut down because of flash flooding.

Several rivers were lapping over their banks, including the biggest one, the Mississippi. In Hannibal, Mo., the flood gates were installed in open sections of the levee that protects the Mark Twain sites and the rest of downtown. Emergency management director John Hark said he was in “full flood fight” mode.

The river was expected to climb nearly 10 feet above flood stage by the middle of next week several spots north of St. Louis, including tiny Clarksville, Mo.

Many of the town’s 442 residents were filling sandbags Thursday as floodwaters began rising toward the unprotected downtown. City Clerk Jennifer Calvin said the Federal Emergency Management Agency was bringing in 500,000 additional sandbags, the effort speeding up because the crest of the flood is expected over the weekend.

“This is a short time frame we have to prepare for it,” Calvin said. “That doesn’t make it any easier.”

Strong storms rolled through the St. Louis area during the morning rush Thursday, snarling traffic with water over several roadways. Winds up to 60 mph caused scattered damage.

In Chicago, the storm-swollen Chicago River was being allowed to flow into Lake Michigan, in part to relieve sewer backups downtown and in neighborhoods. The river was diverted away from the lake more than a century ago to keep pollution out of the lake, the source of the city’s drinking water. Meanwhile, workers were furiously filling sandbags and putting up barricades along the north branch of the Chicago River in the Albany Park neighborhood.

Making flood concerns even worse: Forecasters are calling for the heavy rain to continue in many places into Friday morning.