Suppose – where you live – it’s been an unusually warm autumn for weeks. And then suddenly a cold front comes through and drops not only temperatures, but also a foot of snow. That’s an example of weather whiplash, when your local weather shifts suddenly from one extreme to another. Weather whiplash might be going from a sustained drought to flash flooding, or from cold spells to unusual warmth. Or, for example, we might go from a strangely quiet August during hurricane season to a historic Hurricane Ian striking Florida.
Weather whiplash events disrupt human activities, energy supplies, agriculture and ecosystems, a team of scientists said. They published a new study on the phenomenon this month (September 2022). The researchers said their work suggests that – although weather whiplash events have not increased in recent decades – these events will increase as global temperatures continue to rise.
Atmospheric scientist Jennifer Francis led the research. She’s with Woodwell Climate Research Center (originally part of Woods Hole Oceanographic Institute) in Falmouth, Massachusetts. The researchers published their new work in the peer-reviewed journal JGR Atmospheres on September 7, 2022. The scientists said:
Examples of weather whiplash during 2022 so far are as numerous as they are devastating: A hot, long drought in western U.S. states during early summer was broken by record-breaking flash flooding. Exceptionally wet and cool conditions during June in the Pacific Northwest were replaced by a heat wave in July. A record-warm early winter for most south-central states was followed by a cooler-than-average January and February. The heaviest rains in a century broke a spell of 67 consecutive hot, dry days in Dallas, TX.
Why more frequent? One culprit is the Arctic
The scientists studied a new approach to measuring the frequency of these events. They looked at what happens when one persistent continent-wide circulation pattern shifts to a distinctly different pattern.
They examined the eastern Pacific Ocean and North America over the past 72 years, and they noticed something. That is, when the Arctic was anomalously warm, there were more weather whiplash events. And when the Arctic was cold, there were fewer weather whiplash events. That’s why – although the frequency of these events is currently not increasing – the future is a different story. Co-author Judah Cohen explained in the scientists’ statement:
We know the Arctic region is experiencing the most rapid changes in the global climate system. Evidence is growing that these profound changes are contributing to more extreme weather events outside the Arctic. And this influence will only increase in the future.
Weather whiplash is already all around us
Lead author Francis said:
The spring and summer of 2022 has been plagued by weather whiplash events. A warming planet increases the likelihood of longer, more intense droughts and heat waves, and we’re also seeing these spells broken suddenly by heavy bouts of precipitation, which are also fueled by the climate crisis. These sudden shifts are highly disruptive to all sorts of human activities and wildlife, and our study indicates they’ll occur more frequently as we continue to burn fossil fuels and clear-cut forests, causing greenhouse gas concentrations to rise further.
Francis also tweeted some of examples of weather whiplash.
An excellent example: https://t.co/nUWqW3kCGh
— Dr. Jennifer Francis (@JFrancisClimate) September 8, 2022
And Francis retweeted this video as another great example of weather whiplash.
After long periods of drought, much of Western Europe including France, is now experiencing flash floods. The video below is from Paris.
How many more ‘historic’ events? #ActOnClimate #ClimateEmergency #climate #energy #GreenNewDeal pic.twitter.com/PQMOQtzxxX
— Mike Hudema (@MikeHudema) August 19, 2022
Bottom line: Weather whiplash events are when conditions shift abruptly between extreme weather. Scientists say this type of weather will become more common as the Arctic warms.
Source: Measuring “Weather Whiplash” Events in North America: A New Large-Scale Regime Approach