The annual U.S. winter outlook report predicts that strong La Niña conditions are expected across the country. The US has a 74% chance of La Niña conditions, while there is a 40% chance of this being a moderate event.

According to the National Weather Service, La Niña events are the periodic cooling of ocean surface temperatures in the central and east-central equatorial Pacific Ocean. This period usually happens every 3 to 5 years, but can also occur occasionally. Last year, the US experienced El Niño conditions, which are the opposite of La Niña, meaning the ocean is warming to above-average sea surface temperatures in the central and eastern Pacific Ocean.

During La Niña events, the northern part of the United States typically experiences colder and stormier winter conditions, while the south is warmer and less stormy.