A winter storm warning is issued when there is an 80% or greater chance of a winter storm and conditions pose a threat to life or property. Travel will be difficult or impossible. The following conditions merit a winter storm warning: Snow of at least 6 inches in 12 hours. Snow of at least 8 inches in 24 hours.

A winter storm could cause havoc for Americans from Texas to New York with the possibility of massive power outages and flight cancellations.

A sprawling winter storm is expected to sweep across the United States this weekend, placing more than 160 million people in the path of hazardous wea.

A snowstorm is causing significant travel disruptions across the United States, with flight cancellations and delays affecting travelers at Philadelphia International Airport and beyond.

"It's likely going to affect an estimated 225 million people," said Katy Nastro with Going.