Wintry conditions sweep across the U.S., producing below-average temperatures, winter weather watches and flood watches.

The National Weather Service said the fog could lead to black ice and limited visibility, and urged drivers to exercise caution.

More than 18 million people are under winter weather alerts across the West and Midwest as storms are forecast to bring heavy snows and bitter winds.

There are Winter Weather Advisories in 3 counties within the region, the only threat expected with these advisories is the snowfall above. Webster and Pocahontas Co. can expect 2-4 inches of snowfall, while Braxton Co. can expect 1-3 inches of snowfall. These advisories start at 1:00AM and end at 9:00PM tomorrow.

Winter storm warnings have been issued for several US states across the West and Northwest amid heavy snowfall and dangerous travel conditions in various areas.

Around 20 million people across the West and Midwest are under winter alerts Saturday as a fast-moving storm delivers heavy snow, strong winds and blasts of cold that is blanketing cities like Chicago.

The Tuesday morning commute in northern New Jersey could be messy with a mix of snow, sleet and rain, forecasters say.

Understanding the Watch, Warning, and Advisory Hierarchy Let's be real, the National Weather Service throws around terms like watch, warning, and advisory, and most people just know something bad is coming.