Recent weeks have seen a spate of destructive tornadoes sweeping across vast regions of the United States. Experts attribute this surge, in part, to an unusually warm winter in the South, which has contributed to one of the busiest starts to the tornado season on record.
According to the National Weather Service, there have been at least 478 tornado reports across 25 states this year. Only 2017 and 2008 saw more tornado reports by this time of year, with 503 and 523 reports, respectively.
Understanding how tornado activity will evolve in a warming climate is still under investigation. However, changing risks are increasingly affecting vulnerable regions, especially where social factors exacerbate the impact of extreme weather.
The mild winter has played a significant role in this year’s active tornado season, explained Harold Brooks from NOAA’s National Severe Storms Laboratory. Warmer winters create atmospheric instability in early spring, a key ingredient for severe storms and tornadoes.
“If cold fronts don’t reach the Gulf, even a little wind can bring in warm, moist air,” Brooks said. “This year, cold fronts haven’t reached the southern U.S. as much, leaving the region warmer.”
This pattern explains why the South experiences more tornadoes during cooler months and why the region might face increased risks as global temperatures rise.
A recent study in the Bulletin of the American Meteorological Society predicts that supercell storms, which can generate violent tornadoes, will become more frequent in the South, particularly affecting states like Alabama, Mississippi, and Tennessee.
Walker Ashley from Northern Illinois University noted that the South’s dense population increases the likelihood of tornadoes striking populated areas, compared to the Great Plains. This risk is compounded by socioeconomic factors and the prevalence of mobile homes, which are particularly vulnerable during tornadoes.
So far this year, over 60 tornado-related deaths have been reported, surpassing the annual average of 71. The recent tornado in Rolling Fork, Mississippi, highlighted the severe impact on mobile home residents, with a significant portion of fatalities occurring in such homes.
While the tornado season has started actively, future storm activity remains uncertain, cautioned Jason Naylor from the University of Louisville. The recent tornado surge underscores the need for heightened awareness, especially in areas projected to face more frequent tornadoes in the future.