Track the winter storm as it's forecasted to bring heavy snow and extremely cold weather to the U.S., reaching millions from the southern U.S. to the Northeast.

Officials warned drivers to urge caution as a “prolonged” lake effect snow band was leading to “rapid changes” in weather conditions ahead of the afternoon and evening commutes. Many counties were under winter storm warnings and advisories Friday and Saturday as forecasters warned of an “intense band” of lake effect snow,