TORNADOES

Tornadoes are more common in the United States than in any other country, averaging 1,375 a year. April, May and June are historically the most active for severe weather and tornadoes, with an average of 660 twisters spinning up within that three-month window. By the end of March, 2023, the U.S. had already been struck with 180 tornadoes. Alabama experienced the most, followed by Georgia, Louisiana & Texas. Mississippi (closely followed by Texas) took the most hits in 2022, according to NOAA. Texas, since 1997, has also averaged 135 per year, mainly in April, May & June. 145 tornadoes were recorded in the U.S. from January-March 2024. In April 2024 alone, the U.S. experienced 355 tornadoes, the second most on record behind April 2011. At least one tornado occurred in the U.S. every single day in May 2024 with more than 1,100 tornadoes were reported--a preliminary number but nearly twice the 30-year average at that point and behind only 2011, when deadly tornado outbreaks tore across the southeastern U.S.

• Where are the most tornadoes in the U.S?
  Most often in the midwest's“tornado alley” (which runs through Oklahoma, Kansas, Missouri, Nebraska, Iowa and South Dakota) and “dixie alley".

• How do tornadoes form?
  Instability occurs when warm, moist air is wedged under drier, cooler air aloft. This warm air rises, causing the intense updrafts and downdrafts seen in strong thunderstorms— the incubators of tornadoes.

• What states have never had a tornado?
  Alaska, Rhode Island and Washington.

• What are the top 10 worst tornadoes ever to occur in the U.S?
  The 25 deadliest tornadoes date back to 1840. NOAA has a list here and a brilliant list of FAQs here.

HOW WILL CLIMATE CHANGE AFFECT TORNADOES?

It’s not yet fully understood how climate change will affect tornadoes, due to modeling challenges, high variability and limited data collection. As the most recent National Climate Assessment noted, while the link between climate change and some extreme weather is apparent, “changes in smaller-scale, short-lived severe weather such as tornadoes and thunderstorms are more difficult to assess, and direct observations of those events and the conditions associated with them are incomplete.” 

Some trends have been identified in the US: tornado breaks, clusters and overall strength are increasing, and the distribution of tornadoes has shifted east. 

Climate change may be responsible for the shifting of tornado regions, and the changing seasonality and severity of thunderstorms that may produce tornadoes. Specifically, the number of days favorable for tornadoes is expected to increase, and tornado season may start earlier. “Tornado Alley" is widening - with outbreaks occurring less in the Great Plains, and more often in the Southeast and Midwest. 

As tornado season and tornado alley are changing, the most important thing is to be educated and prepared.