The National Oceanic and Atmospheric Administration (NOAA) is examining December’s tornado outbreak and gathering data to help explain why it occurred in late autumn.
The research, which is studying the occurrence of 61 tornadoes as of Dec. 18, is focused on the correlation between extreme weather events and climate change, an NOAA press release said.
“The very fact that tornadoes of this intensity struck in late autumn, rather than in the spring and summer when thunderstorms and tornadoes are more likely, is remarkable,” NOAA said in the release.
NOAA has found that warmer winter temperatures as a result of climate change likely contributed to increased thunderstorms. “Those storms then became tornadic because they developed in an environment where the horizontal winds from the ground up to about 20,000 feet increased significantly,” the release said.
“Attributing a specific tornado to the effects of climate change remains challenging,” NOAA said in the release. “However, we can say that warmer winter temperatures attributed to climate change are projected to create conditions that make tornadoes more likely.”
A series of tornadoes devastated communities in eight U.S. states on Dec. 10, killing more than 80 people and causing significant property damage.
NOAA estimates that a tornado happening in December is 12-15%, compared to the probability of an early June tornado at 90%, the release said. While rare, December tornadoes have been known to occur, with “22 EF-4 and EF-5 category tornadoes — the most destructive —” occurring since 1879.
