About 80 million people living in the southeastern United States are under a weather alert for the massive and powerful winter storm that has left about 240,000 people without electricity and forced airlines to cancel thousands of flights throughout the region, writes canberratimes.com.

The National Weather Service predicted heavy snowfall mainly for the states of Georgia, North and South Carolina, Tennessee and Virginia due to a cold front that will sweep toward the northeast and the lower portion of the Great Lakes during the course of the day, moving on into Canada by Tuesday.

In Canada, the storm is forecast to dump between 20 to 40 centimetres of snow through Monday morning over parts of southern and eastern Ontario, the Canadian province that shares part of its border with New York state, the government weather agency, Environment Canada, said.

The inclement weather hits just as Ontario schools were set to reopen for in-person classes on Monday after the winter break was extended because of the highly contagious Omicron coronavirus variant.

More than 3000 flights within, into or out of the United States were cancelled on Sunday, and more than 8000 flights were delayed, according to FlightAware data.