Linking Climate Change To Some Weather Events Are Easier Than Others: ‘Making The Connection To Tornadoes Is The Hardest Of All’

December 11, 2021

Piggy-backing on the tornado story from earlier as the question of climate change enters the picture of wreckage as we see twisters of such extreme, and nearly-rare and unusually violent storms, that wrecked the mid-west last night.
However, unlike the heat waves from last summer where those high temperatures “…would have been virtually impossible without climate change,” tornadoes are another breed.
Via The New York Times:

Tornadoes are relatively localized short-lived weather events. And scientists are not yet able to determine whether there is a link between climate change and the frequency or strength of tornadoes, in part because they have a limited data record.

But researchers say that in recent years tornadoes seem to be occurring in greater “clusters,” and that a so-called tornado alley in the Great Plains — where most tornadoes occur — appears to be shifting eastward.

“This is what we would call a tornado outbreak, where you have a storm system which produces a number of tornadoes over a large geographical area,” Dan Pydynowski, a senior meteorologist with AccuWeather, said on Friday.

And maybe monster twisters:

Mayfield was in the track of a twister more than a mile wide and cut a path of destruction for more than 220 miles — nearly three hours tearing up the ground before becoming airborne.
An aside in climate change context this afternoon from Edward Helmore at the Guardian‘s live blog:

President Biden gave a careful response when asked on Saturday about whether he believed tornados that have caused such damage in the US overnight were linked to climate change.

Scientists have been wary of attributing the frequency and intensity of convective storms that can produce tornadoes to climate change, in part because historical and observational data around tornadoes is relatively limited.

In simple terms, that’s due to fact that tornadoes are relatively small and can easily go unreported, says Michael Tippett, a professor of applied mathematics at Columbia University and co-author of a study published last month by the American Geophysical Union.
“In linking climate change to extreme weather like hurricanes or extreme rainfall and flooding some connections are easier to make than others,” Tippett told The Guardian on Saturday.
“Making the connection to tornadoes is the hardest of all.”

Studies have found that severe thunderstorms accompanied by tornadoes, hail, and damaging winds cause an average of $5.4bn of damage each year across the US, and $10bn events are no longer uncommon.
In the recent paper, Future Global Convective Environments, the authors looked at the atmospheric ingredients necessary to produce extreme weather that could in turn produce tornadoes. The authors projected that for each degree of global temperature increase, conditions favorable to severe weather increased by 5-percent–20-percent.
“We have circumstantial evidence, yes, but the key caveat is that favorable conditions do not guarantee that a storm occurs,” Tippett said.

Some scientists have been able to establish that the number of tornadoes in large tornado outbreaks is on the rise and the weather environments that produce severe storms are occurring more often.
Each year, tornadoes are starting about a week earlier in “Tornado Alley” from Nebraska to Texas, while summer tornado frequency is declining.

Perhaps relevant to the deadly toll in the Kentucky event, tornado frequency is increasing in winter months, and at night, when they are 2.5 times as likely to cause fatalities, are occurring in an area known as “Dixie Alley,” including Arkansas, Louisiana, Mississippi, Alabama, and Tennessee.
Another circumstantial piece to the puzzle is that the five largest US winter tornado outbreaks have all hit since 1999. “Scientists say this is the toughest nut to crack when it comes to connecting climate change and its impact on weather extremes,” says Tippett.
“Circumstantial evidence points to an increase in frequency, but it’s not a direct line of evidence. Intensity is a whole other can of worms.”

No matter, climate change won’t help, though. In describing climate change’s major force-impact now, most-likely the key word would be, ‘exacerbate‘ — make shit worse. Apparently, tornadoes are a sticky-point.
A good, fairly-thorough look at this came last July from noted meteorologist and journalist Bob Henson at Yale Climate Connections — a must-read in its entirety:

Climate change may be the existential threat of our lives, yet when it comes to in-your-face weather, tornadoes are in a class of their own. Fortunately, human-warmed climate isn’t making violent U.S. tornadoes any more frequent.
However, climate change may be involved in some noteworthy recent shifts in the location and seasonal timing of the tornado threat.

The United States is the global epicenter of tornado formation. An average of about 1,200 U.S. twisters are observed each year, with some years bringing as few as 900 and others as many as 1,600-plus. It’s all the result of a unique geography that allows hot, dry air from the Southwest to flow atop moist, warm, unstable surface air east of the Rockies, with cold air at the jet-stream level overtopping it all.
This layer cake of winds and air masses, varying with height, supports development of rotating supercell thunderstorms, the kind that produce the most long-lived and intense tornadoes.
Even weaker non-supercell storms can collectively spawn hundreds of twisters each year.

Each tornado is a localized creature, which makes it difficult to link to global climate trends. Climate change typically plays out in local fashion by way of broad regional shifts, such as depleted sea ice, warmer oceans, and drier landscapes.
Sometimes these shifts are distinct enough from natural variation to signal clearly that human-caused climate change is likely involved. In contrast, tornadoes and their parent thunderstorms are brief and episodic, and they normally vary a great deal over time and space, so it’s tougher to distill long-term trends in their behavior and distinguish those from normal ups and downs.

And a bottom line: Even in these high-resolution models, tornadoes themselves are far too small to be directly simulated, so that reality remains a major caveat.

Twister situation will get worse in shorter bursts, no way it can get better.

Here we are, once again…

(Illustration out front: Pablo Picasso’s ‘Agonizing Horse,’ found here),

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