It’s tornado season again, again.
Well, folks, it’s tornado season again. Thankfully this year we will be spending it in Colorado where the the threat of tornados remains low.
This is an update to an article from last year due to current events.
Last week, two consecutive and severe tornado outbreaks wreaked havoc across various regions in the Midwestern and Southern United States putting the US tornado count back in line with the 2005-2023 mean (2024 is red line below and mean is black line).
The first of these, known as the Arbor Day Tornado Outbreak, occurred on April 25 and 26. During this event, Lancaster County in Nebraska witnessed a significant tornado that injured multiple individuals. Concurrently, northeastern Lincoln, Nebraska, also experienced a tornado.
The outbreak proved deadly, resulting in multiple fatalities and injuring over 150 people. A total of twenty-eight tornadoes were confirmed, with a notable concentration in Iowa and individual tornadoes striking Nebraska and Texas. Particularly severe damage was reported in Blair and Elkhorn, Nebraska.
The subsequent day, April 27, saw another series of tornadoes, primarily affecting Texas, Oklahoma, and Kansas. A significant tornado struck Holdenville, Oklahoma, overnight, causing multiple deaths and injuries. Another tornado in Sulphur, Oklahoma, resulted in many injuries.
The meteorological conditions leading to these outbreaks were attributed to supercells advancing through eastern Nebraska and western Iowa, fueled by a combination of an upper-tropospheric trough and a moist air mass moving into the region.
As with most weather events, this outbreak was linked to climate change by the media rather quickly…
However, there is no correlation between the frequency and intensity of tornadoes and climate change. Read the original article below
How does a tornado form?
Tornadoes form from rotating columns of air that extend from thunderstorm clouds to the ground. There are several factors that can drive tornado formation, including atmospheric instability, wind shear, and convective available potential energy (CAPE).
Tornadoes typically form within a supercell thunderstorm, which is a type of thunderstorm with a deep, rotating updraft. Supercells can form in regions with high atmospheric instability, which is caused by a combination of warm, moist air at the surface and cooler, drier air aloft. Once a supercell thunderstorm forms, the updraft can tilt the rotating air from horizontal to vertical, creating a mesocyclone, which is a rotating column of air that is several miles wide.
As the updraft intensifies, the rotating column of air stretches and spins faster, creating a stronger mesocyclone. The updraft also draws in warm, moist air from the surface, which contributes to the development of the thunderstorm and the tornado. This spinning air cools and lowers the pressure in the center of the mesocyclone, and moisture in the air condenses into a visible funnel cloud.
The funnel cloud extends from the base of the thunderstorm cloud toward the ground. If the spinning column of air reaches the ground, it becomes a tornado. The tornado can then move in any direction depending on the wind patterns within the thunderstorm and the surrounding environment.
Several factors contribute to tornado formation. As mentioned earlier, atmospheric instability is a key factor in the formation of tornadoes. Instability is caused by differences in temperature and moisture at different levels in the atmosphere. When these differences are high, they can create strong updrafts that help to initiate tornado formation.
Wind shear, or the change in wind speed or direction with height, can create a rotating column of air in the atmosphere. This rotating column can be stretched and intensified by the updraft in a thunderstorm, leading to tornado formation. Convective available potential energy (CAPE) is a measure of the amount of energy available in the atmosphere for convection, or the upward movement of air.
Higher CAPE values can lead to stronger updrafts and more intense thunderstorms, which can increase the likelihood of tornado formation. Other factors that can contribute to tornado formation include the presence of a boundary between different air masses (such as a cold front or dry line), topography, and interactions with other thunderstorms or weather systems.
Source: https://www.geoteach.org/projectGO/tornadoes/background.php
How has climate change influenced the frequency and intensity of tornadoes in the USA?
The number of tornadoes and the amount of damage caused by tornadoes in the US has increased over the past few decades. But is that evidence of an increase in the frequency and intensity of tornadoes due to climate change, or are these claims more propaganda than scientific truth?
Here are a few statistics on tornadoes in the US:
- The number of tornadoes reported in the US has increased over the past few decades, but it is unclear whether this is due to actual increases in tornado activity or improvements in tornado reporting and detection.
Source: https://lincolnweather.unl.edu/graphs-us-tornadoes-fatalities-tornado-days
However, in order to account for the advancement in recognition of small EF0-2 tornadoes let’s look at the data for larger tornadoes (box ‘b’ in the figure below, which is data for EF3+)).
Source: https://ascelibrary.org/doi/full/10.1061/%28ASCE%29NH.1527-6996.0000295?casa_token=SmtxXsEoDXUAAAAA%3AqP5dkZoP318lCCFBfN-MbCiJ_2NSaZ4JJM8IeW7fff3ZnODsocN4S95QdjroHNUhWYLKl02sMtM-
It’s clear from the above data that the increase in total tornadoes in the USA has been due to technological improvements in the recognition of small tornadoes (EF0-2), while larger tornadoes (EF3+) have actually decreased in the count since 1950 despite the continued warming and release of anthropogenic CO2. Thus, it appears the claim that climate change is increasing the frequency and intensity of tornadoes is false.
- The average number of tornado-related fatalities per year has decreased since the 1950s, largely due to improvements in tornado warning systems and public education efforts.
Source: https://lincolnweather.unl.edu/graphs-us-tornadoes-fatalities-tornado-days
- However, the economic cost of tornadoes has increased significantly in recent years, in part due to factors such as urbanization and increased property values in tornado-prone areas. Note: CPI-adjusted does not account for the transfer of populations and wealth and thus is a poor way of normalizing the cost of natural disasters.
Source: https://www.climate.gov/news-features/blogs/beyond-data/2021-us-billion-dollar-weather-and-climate-disasters-historical
When normalized to GDP, a much better way of accounting for population, wealth, and infrastructure increases we see there has been a steady decline in cost, likely due to the decrease in EF3+ tornadoes discussed above.
Overall, improvements in tornado forecasting, warning systems, and engineering of structures have helped to reduce both the number of fatalities from tornadoes and the economic cost of tornadoes as a function of GDP.
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Tom
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New “Twisters” movie coming this summer. If there were no people or fewer people living in tornado prone areas, none of these “scare” tactics would matter. It’s as simple as that…fewer people, less infrastructure = less loss.
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VOWG
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I have been saying that for a long time now. At the end of WW2 there were about 2.4 billion people on the planet now there are over 8 billion. Millions living where millions never lived before.
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Jerry Krause
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Hi Tom,
Have a question for you because you frequently comment. The question should be asked of Dr. Wielichi, or even better. NOAA but I doubt if either of these two are actually reading PSI comments.
To identify the “tornado season” it would seem to better to plot the number per month and compare these monthly numbers over the sequence of years. Much of the focus seems to be upon why tornados occur, which certainly is a valid effort. But I consider an equally valid question is why tornados don’t occur more often. Especially, do El Niño events have an influence,. I consider La Niña events to be just super normal weather but it would seem quite meaningful if these ‘abnormal’ weather events did seem to have an influence.
My final comment is we can study weather and possibly predict weather, but we cannot change weather. It just NATURALLY happens.
Have a good day
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Jerry Krause
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Hi PSI Reader,
In OUR AMAZING WORLD OF NATURE all articles are brief and most are based upon the personal experience of the author. The 2nd article is by Jean George and titled A TOOTH AND A CLAW. It begins: “Once in a clover-spattered meadow I watched two cows cracking their heads together with such violence that I winced and asked the farmer why he didn’t separate the animals. “Cow fights,” he drawled, “make for order and peaceful individuals. The sooner those two decide which is gonna be boss, the sooner I’ll get bucket of milk from each of them”
“In his lifetime with cattle this farmer had seen what science is now establishing: that animal aggression is creative. Tooth-and-claw encounter is a positive adjustment to an irritating situation, as sleep is an adjustment to fatigue, eating to hunger.
Have a good day
Reply
Jerry Krause
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Hi PSI Reader,
I am intrigued by the book OUR AMAZING WORLD OF NATURE and I started to reread it from its beginning and I discovered A TOOTH AND A CLAW by Jean George was the 3rd article and that the 2nd critical was also by her and titled THAT ASTOUNDING CREATOR–NATURE. As a Christian and I believer in the Creator God (The Father) and this title troubled me.
However, near the end of this book with its many beautiful photos I read this–“The beauty of nature is not just the joys of the senses. The Psalmist knew it when he lifted up his eyes to the hills. Hills and valleys made for homes, and and the stars over them–from these comes our help. For the deepest beauty of the natural world lies not in its sheen and color, but inits order and meaning. On this agree both the scientist and the religious teacher. When you make room for beauty, you cast out ugliness.” (pp 309, Donald Culross Peattie)
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