Winter weather grips the US

10:59 a.m. ET, February 20, 2019

Thundersnow sweeps through Ohio and Maryland

Intense snow bands moving through the areas are putting on a show today.

An Ohio Department of Transportation picked up some thunder bolts and lightening early this morning.

Later in Cumberland, Maryland, some intense rolling thunder echoed across the area.

What is thundersnow anyway? In simple terms, it is when a storm is strong enough to have thunder, but still cold enough to still have snow and not rain.

The snow will reflect the light, making it seem like you could be standing in a cloud and acts as a dampener, muffling the thunder. It can even act like a prism for the lightening, creating different colors of light like green and blue.

10:25 a.m. ET, February 20, 2019

What to expect on the West Coast

The winter storm brining snow and sleet to much of the East Coast isn't the US's only one: Another storm will impact much of the west with more snow and cold over the next couple of days.

Here's what we're looking out for:

  • Winter watches, warnings advisories stretch from the Mexican to Canadian border
  • Las Vegas is under a winter weather advisory, with up to an inch or two of snow forecast.
  • Heavy snow is expected to fall in the mountains of Southern California.
  • Freeze warnings continue for Phoenix.
10:20 a.m. ET, February 20, 2019

Most of the Eastern US will get snow, sleet or freezing rain

A potent winter storm is poised to deliver a mixture of snow, sleet, freezing rain and possible flooding across much of the eastern United States through Thursday.

More than 117 million people in the country, many from the Plains and Midwest to the Mid-Atlantic and Northeast, are under some sort of winter weather watch, warning or advisory. Nearly 20 million are facing a flood warning, watch or a flash flood watch across the Southeast.

Warm moist air streaming north from the Gulf of Mexico will combine with a colder storm system exiting the Rockies to create an expected wintry mix Tuesday night into Wednesday.

Heavy rain fell in the South throughout Tuesday.

Much of the Pacific Northwest is also under winter weather warnings or watches.