The first major winter storm of the new year barreled into the U.S. mid-Atlantic states. The US National Weather Service (NWS) estimates that approximately 60 million people are affected by the storm.
Snow and ice blanketed major roads across Kansas, western Nebraska and parts of Indiana, where the state's National Guard was activated to help stranded motorists.
Severe travel disruptions were expected across the storm's path, and officials urged drivers to stay off the roads if possible.
A state of emergency was declared in Kansas, Missouri, Maryland, Kentucky, Virginia, West Virginia, Arkansas, Washington DC and parts of New Jersey.
Nearly 300,000 customers were without power early Monday across Kentucky, Indiana, Virginia, West Virginia, Illinois and Missouri, according to electric utility tracking website PowerOutage.us.
In the wake of the storm, dangerously frigid Arctic air was filling the void, bringing freezing rain and icy conditions to a swath of the country stretching from Illinois to the Atlantic coast. The unusually cold temperatures are expected to linger for the rest of the week.
The NWS warned that up to 12 inches (30.48cm) of snow are expected to fall from Ohio to Washington DC in the early hours of Tuesday.
The polar vortex of ultra-cold air usually spins around the North Pole. People in the US, Europe and Asia experience its intense cold when the vortex escapes and plunges southward.
Studies show a fast-warming Arctic is partly to blame for the increasing frequency of the polar vortex extending its icy grip.
The Central Plains, where the storm dumped heavy snow over the weekend, were already in a deep freeze. Parts of Kansas experienced bitter cold wind chills, with values from 5 to almost 25 degrees Fahrenheit below zero (minus 15 to 32 degrees Celsius) overnight. The cold air will persist, with daytime highs only in the mid teens to lower 20s.
Kansas was hit the hardest by the snowfall, the NWS recorded 18 inches (45.72cm) of snow.