The flood, fueled by more than 10 inches of rain over a three-day period that began last weekend, is blamed for 22 deaths.
A Utah teen survived being lost overnight in single-digit temperatures over the weekend.
Officials closed a major interstate highway south of St. Louis on Thursday morning amid historic flooding.
The U.S. Army Corps of Engineers said water from the rising Mississippi River and its tributaries threatened to spill over 19 federal levees
Torrential rains pushed already swollen rivers and streams to virtually unheard-of heights in parts of Missouri and Illinois.
Interstate 44 was closed near the central Missouri town of Rolla, and a section of Interstate 70 was shut down in Illinois.
Heavy rain has caused flooding in southeast Kansas, where several roadways have been closed because of high water.
After a December that has felt more like spring than winter, the first major snowstorm of the season is about to hit the Northeast.
The storm system that spawned the twisters brought winter storm woes to the Midwest on Monday.
City crews have completed their third pass through the priority routes.
The Oklahoma Highway Patrol is searching for two hunters missing in Kay County.
More than 1,400 flights have been canceled across the U.S. and 2,600 have been delayed.
Authorities say more than 180 Missouri roads are closed because of flooding.
Forecasters say two tornadoes that hit the Dallas area had winds up to more than 200 mph.
In Albuquerque, police say officers responded to 178 weather-related accidents by 9:30 p.m. Saturday.