It is just the start of 2025, but the U.S. is already seeing extreme weather across the country, from the wildfires raging in southern California to the uncharacteristically heavy snow in the Southeast and it seems that the return of La Niña may be responsible for some of it.

At least 46 million people were under a winter storm warning as of Thursday as the storm spreads along the Gulf Coast Friday, according to the weather service. The storm should weaken by Saturday, bringing lighter snow between 1 and 3 inches to parts of the Northeast, the Mid-Atlantic and the Ohio Valley before exiting off the Carolinas.

The National Oceanic and Atmosphere Administration announced this week La Niña has arrived. This usually means the northern parts of California and the U.S. see more rainfalls where as Southern California sees less rain.