Tuesday’s historic snowstorm reportedly dumped up to 11.5 inches of snow across the Greater New Orleans area, likely shattering snowfall records.
Climatologist Barry Keim said this week’s storm had clear parallels with the region’s last “mammoth” snow event 130 years ago. The 1895 snowstorm resulted from a similar mix of rare conditions. The biggest factor? Extremely cold temperatures over a long period of time. Keim says this blast of cold air likely came from the Arctic as part of the “polar vortex.”
The “polar vortex” is an area of cold air and low pressure that always exists around the Earth’s poles.
“ Anytime we get an Arctic air blast down this far south, this is an artifact of the polar vortex rearing its ugly head,” said Keim.
So far, November and December have been warmer than average in Louisiana, aligning with a global trend of milder winters. But this week, the state saw record-low temperatures. How does a warming world square with one of South Louisiana’s most bitter freezes?
Keim shrugged his shoulders because scientists haven’t drawn a conclusive link between climate change and Gulf winter storms like this one or the 2021 snowstorm in Texas.
His own research has supported the warming trend, finding that Louisiana — and the rest of the country — is seeing fewer freezes each year. But he thinks this storm serves as a reminder that just because the world is getting warmer, deep freezes can still happen.
“ This is a great example that, yes, the atmosphere can still wind itself up and throw some pretty interesting, unusual and cold events at us on occasion,” Keim said. “ It's Mother Nature just throwing another little wrinkle at us to keep us honest.”
Plenty of climate scientists believe these visits from the polar vortex could just be a wrinkle. There’s still a lot that researchers don’t know about weather and climate, and this involves a lot of complicated atmospheric processes. But some emerging science suggests that, generally, the polar vortex could be changing as a result of global warming, possibly causing more cold extremes in North America.
Warming temperatures at the poles and melting sea ice could be disrupting the polar vortex, destabilizing it causing it to stretch south and cause extreme cold snaps more often, according to studies from 2021 and 2024. This would happen even as the overall temperature continues to increase.
Amy Butler, a scientist at the National Oceanic and Atmospheric Administration who studies the polar vortex, said, long term, the models don’t agree on what changes to the polar vortex may be long term. The historical data only goes back about 60 years so the record isn’t long enough to distinguish if there have been any changes so far. She says any perceived change could just be natural variation.
“Whether the vortex ‘stretching’ events will increase in the future has not been well studied and I don't think there is much evidence either way,” Butler said.
Both Butler and the authors of the 2021 study agree on one thing: although far fewer of these cold extremes occur in the future, they will still happen from time to time. And when they do, they may be even more challenging.
“It will be harder for society to deal with because we become unaccustomed to dealing with this type of cold,” Butler said.
In the 2021 study, the authors said that preparing only for warmer winters will compound the economic and human cost of the rare winter storm when it does occur.
Last year, the rapid warming of the Arctic resulted in a dramatic switch. The icy region no longer stores more carbon than it releases after reporting some of its highest temperatures and lowest amount of sea ice. Researchers are looking to see how the melting of the world’s iceboxes could affect climate and weather patterns, since historically the poles have helped to cool the planet and shaping jet streams
