(NBC) – After getting off to a relatively quiet start, tornado season in the United States is picking up steam, with experts predicting that conditions are ripe for a supercharged storm season.
The forecast for an active tornado season is being driven by a strong La Niña, a naturally occurring climate pattern that creates favorable storm conditions across the southern U.S. This is of particular concern to scientists because some of the country’s most severe tornado outbreaks have happened during La Niña events, including the 2011 tornado season, which was one of the costliest and deadliest in recorded history.
Tornado activity has already increased in recent weeks, but the season is expected to ramp up considerably in April, said Victor Gensini, an associate professor of atmospheric sciences at Northern Illinois University. “We’re likely going to see another significant event this week in vulnerable areas like Mississippi and Alabama, and then things are likely going to be pretty active next month,” he said.
The most significant driver of this uptick in activity is La Niña, Gensini said, which is characterized by cooler-than-average waters off the western coast of South America that then influence weather patterns around the world. La Niña — similar to its counterpart, El Niño — affects the positioning of the jet stream, a ribbon of fast-moving air that is powered by temperature differences between the cooler polar region to the north and warmer air masses to the south. READ MORE
