MOLINE, Ill. — This March has been pretty quiet when it comes to severe weather, unlike the past two years.
In March of 2022, the U.S. experienced the most tornadoes on record since 1950, when records began. The National Weather Service reported 234 tornadoes in March of that year. The strongest tornado in all of the U.S. last March was the EF-4 tornado that occurred in Winterset, Iowa.
March 2021 had about 100 fewer tornadoes than in 2022. On average, 92 tornadoes occur in the month of March. As of March 26, there have been 44.
Are we experiencing severe weather earlier?
Northern Illinois University Associate Professor Victor Gensini told CNN, “Our future projections of how severe weather may change in the future are really showing two things. They kind of show an earlier start to the severe weather season — so more severe weather in February, more severe weather in March — and then also sort of this eastward increase."
March 2022's record number of tornadoes could have been caused by the La Niña climate pattern.
“If you look back through history, some of our greatest or most significant tornado seasons in history have been associated with a La Niña,” Gensini said.
That can occur due to the active jet stream in the southern part of the U.S. and warm temperatures and ocean temperatures in the Gulf of Mexico, creating ideal conditions for severe weather in the mid-south and southeast.
As of March 9, the La Niña season has transitioned into neutral/normal conditions, which means we are no longer being impacted by a La Niña or El Niño climate pattern.
We will continue to do more research on if severe weather is starting earlier. For now, it does appear that a La Niña climate pattern does impact severe weather overall.