A major winter storm sweeping the US this week may bring the coldest Christmas in four decades to parts of the country, say forecasters.
The “once-in-a-generation” cold snap – which began in the Pacific Northwest on Tuesday, before churning east – will become a “bomb cyclone” by Friday.
More than 90 million people are under winter weather alerts across 37 states.
About 80% of the nation is set to experience sub-zero temperatures, including places as far south as Texas
