Tens of millions of Americans are bracing for a massive winter storm that could bring heavy snowfall and the coldest temperatures in more than a decade.
The National Weather Service (NWS) said the storm, which began in the central United States, will move eastward in the next two days.
A state of emergency was declared in the states of Kentucky and Virginia Parts of the United States unaccustomed to extreme cold, including Mississippi and Florida, have been warned to expect treacherous conditions.
Meteorologists say the severe weather is caused by the polar vortex, an area of cold air circling the North Pole.
“For some, this could be the heaviest snowfall in more than a decade,” the National Oceanic and Atmospheric Administration said.
“This could result in the coldest January for the United States since 2011,” AccuWeather forecaster Dan DeBaudouin said.
He added that “temperatures well below the historical average” could persist for a week.
Those low temperatures will be on the East Coast as well, where the storm is expected to arrive Sunday evening.
In the central United States, there will be “significant disruptions to daily life,” “dangerous or impossible driving conditions, and widespread closures” through Sunday, according to the National Weather Service.
Some areas of Kansas and Indiana could see at least 8 inches (20.3 cm) of snow.
In parts of the Midwest, blizzards are possible.
“Power outage conditions will make travel extremely dangerous, with impassable roads and a high risk of motorists being stranded,” the Met Office warned.
Snow and freezing rain is expected in Missouri, Illinois, and large areas of Kentucky and West Virginia.
As the storm moves east, millions of Americans will see record low temperatures, forecasters said.
Cities including Washington, D.C., Baltimore and Philadelphia are bracing for snowy and icy conditions Sunday into Monday. Snowfall ranging from 5 to 12 inches is possible in parts of Virginia.
Also on Sunday, parts of the southern United States, including Arkansas, Louisiana and Mississippi, may see severe thunderstorms.
“It's going to be chaos, potential disaster. This is something we haven't seen in a long time,” private meteorologist Ryan Mau said.
American Airlines, Delta, Southwest and United are waiving change fees for passengers due to potential flight disruptions.