National Weather Service

Even when skies are clear, air pollution can affect the health of sensitive groups.

A sudden dust storm caused low visibility conditions that led to 72 vehicles colliding on Interstate 55 in Illinois on May 1. Seven people died, and 37 others were injured.

While the Mississippi River produced major flooding in parts of northern Illinois, Wisconsin, Iowa and Minnesota, it is expected to crest well below serious flood levels in the St. Louis area this weekend.

Many cities in the Upper Midwest have seen the river already reach its crest, as the water moves down through the system.

States in the Midwest and South have already seen many deadly tornadoes so far this year. These parts of the country are also where the number of severe events are steadily increasing.

The National Weather Service predicts steady snowfall beginning at midnight with up to 8 inches on the ground in parts of metro St. Louis.

Most roads were passable Friday following Thursday’s snowstorm, but brutally cold winds kept blowing. Thursday night had the ninth-lowest windchill ever recorded in St. Louis.

The most hazardous conditions, including extreme cold and blizzard conditions, are behind the initial front.

Road crews are preparing for a blizzard Thursday expected to bring bitter cold and deadly wind chills just as Christmas travel begins.

A major snowstorm is coming to the Midwest and Great Plains during some of the busiest days for travel this year. Here’s how to stay safe while driving, especially on rural roads.