Biden urges Americans to travel early with a large blizzard slated to hit the U.S.

President Joe Biden warned Americans traveling ahead of the Christmas holiday weekend to watch out and leave early if possible to avoid the large storm expected to hit several states Thursday night.

“This is just not like a snow day whenever you were a child,” Biden said. “That is serious stuff.”

Biden was briefed by officials from the National Weather Service and FEMA within the Oval Office Thursday morning. Large swaths of the continental U.S. are under blizzard, ice storm and winter storm warnings. Other areas are under wind chill, freeze and flood warnings.

The National Weather Service website warns of a “widespread and dangerous arctic blast” approaching which can cause “life-threatening cold” and “devour much of the lower 48.” The Midwest and Great Lakes regions are expected to receive the majority of the blizzard with nearly all the Great Plains region under a wind chill warning. The storm will “produce widespread disruptive and potentially crippling impacts across the central and eastern United States.”

Airlines canceled greater than 2,800 flights from Wednesday through Friday, in response to tracking site FlightAware. That period includes what airlines expected to be the busiest travel times before Christmas, which is Sunday.

American, Southwest, United, Delta, Spirit, JetBlue, Alaska and other airlines issued weather waivers for dozens of destinations across the country, allowing travelers to vary their departures without paying a change fee or difference in fare.

No matter how they plan to travel, Biden encouraged Americans to hearken to guidance and watch out.

“I encourage everyone, everyone to please heed the local warnings,” Biden said, adding information may be found on weather.gov.

Biden said the White House has tried to contact governors of 26 states slated to be hit by the storm.

CNBC’s Leslie Josephs contributed to this text.