A winter storm that brought snow, sleet and freezing rain to a large swath of the Midwest swept into the mid-Atlantic and Northeast on Thursday, causing treacherous travel conditions, prompting school delays and closures and potential power outages for millions of Americans.

A powerful winter storm is bringing heavy rain, snow, and dangerous ice accumulations across the U.S., disrupting travel, closing schools, and increasing power outage risks. Authorities urge caution as conditions worsen into next week.

A winter storm is expected to bring snow and ice to the Midwest and Northeast beginning Wednesday. Here's which states will be impacted.

A winter storm covered the Northeast and Midwest regions of the United States with snow and ice on Feb. 5-6 prompting school closures across the regions. Sightings of lightning and thunder snow have also been reported.

"February is kicking off with a very stormy pattern," AccuWeather meteorologist Bernie Rayno said. "A parade of three winter storms will bring snow, ice and sleet to millions of people from the Midwest through the Northeast.”