A massive winter storm is threatening much of the U.S., with 13 states declaring emergencies and an estimated 230 million people in the path of extreme cold, snow, ice, and power outages.

The storm, originating in the Rocky Mountains and Great Plains, is expected to hit the southern states first and move across the Midwest and East Coast, reaching Maine by Sunday.

Officials warned of dangerous travel, prolonged electricity outages, and disruptions to supplies, as residents stocked up on essentials and airlines canceled thousands of flights.

The extreme weather, caused in part by disruptions to the polar vortex amid climate change, is bringing unusually cold temperatures to southern states and heavy snow to northern regions, The Guardian has reported.

FEMA and local authorities are mobilizing to respond, while New York and other states prepare for severe conditions and thick snow accumulations.