Why tornado outbreaks happen in the East during winter and not in Tornado Alley: report

Another winter of storms breaking out across the southeastern United States is reviving the conversation about the "movement" of the so-called "Tornado Alley," which is what the central U.S. is sometimes called. There are also questions about how climate change is bringing more deadly outbreaks year-round. The evidence shows it isn't what you might think.

Over the weekend, Tennessee had a tornado outbreak that spun an EF-2 and EF3 tornado, which brought with them 111-135 mph winds and 136-165 mph winds respectively. Six people were killed, including three who were sheltering in a trailer. Those three included a mother and her 2-year-old son.

In the middle of the country, storms tend to break out more in the spring. In the winter months the Jet Stream shifts, the National Oceanic and Atmospheric Administration (NOAA) says. With it, the warm moist air coming from the Gulf of Mexico clashes again with cool dry air coming from the Arctic. When the two air masses come together they create the conditions ripe for tornadoes and severe storms to form.

Such was the case with a Jan. 16, 2023 outbreak in which a tornado touched down in eastern Iowa. The Dec. 10, 2021 outbreak, however, set the record for the most tornadoes in the winter, with 71 confirmed tornadoes in 24 hours. Mayfield, Kentucky, in particular, was completely devastated.

Scientific America crafted an attempt at trying to explain that somehow Tornado Alley was shifting, but it takes into account only They collected all of the data of tornado outbreaks from 1950-1980 and put it in one data set and large tornado outbreaks from 1989-2019. They plotted them all on a map, but only looked at "a large outbreak defined as a day when eight or more counties experience tornadoes of strength EF-1 or higher."

There is not enough data available to chart all of the tornadoes between 1950 and 1980 to compare to tornadoes from 1989 to 2019. The report never explains why there are nine years missing in their data. The leaps in both technology and detection have changed so drastically that there simply isn't enough information to reasonably conclude Tornado Alley has "shifted."

National Geographic explains that there's no real evidence that shows there are a greater number of tornadoes happening in the United States either. The problem with the data, they explain, is that it's woefully inadequate. Looking at the track record of tornadoes from the 1950s through the 1980s lacks the same scientific standards used to measure tornadoes. In fact, it lacks all of the meteorological standards today.

The Fujita Scale wasn't introduced until 1971, which ranked tornadoes by how much they destroyed. So, no scale existed for storms prior to that data, NOAA says. There wasn't a way to calculate the wind speed in or around the funnel unless it happened to mow over a tool that measured it.

The problem with the F-Scale system, however, was that it required qualified meteorologists and engineers to observe, analyze and report their findings. There were parts of the country where a powerful tornado could have dropped down, but due to the small population, it may not have even been reported, much less measured. As National Geographic explains, the U.S. population was half the size in 1950 to what it is today.

While Doppler radar was utilized by the military in the 1940s and by air travel starting in the early 1950s, it wasn't until Dick Doviak moved to Oklahoma in 1971 that the National Severe Storms Laboratory began using the radar to monitor storms, NOAA recalled in his 2021 obituary.

The "Enhanced Fujita Scale" was established in 2007, Weather.gov said. That's when modern technology came together to calculate both the conditions and destruction due to a tornado. So, mapping tornadoes for 60 years with a 21st-century scale, and using incomplete data puts researchers in a quandary for how to properly chart whether or not the storms are increasing in number or in size. The only real apples-to-apples comparisons come from more advanced radar after 1971 and the availability of better technology that can measure the storms in real time, which wasn't broadly available until at least the mid-1990s.

"A lot more are being recorded now than in 1950, but a closer look at the data shows the increase is only in the weakest category, EF0. There's been no increase in stronger twisters, and maybe even a slight decrease in EF4s and EF5s," the National Geographic explained. "That suggests we're just spotting more of the weak and short-lived tornadoes than we did back when the country was emptier (the United States population in 1950 was less than half what it is now), we didn't have Doppler radar, and Oklahoma highways weren't jammed with storm-chasers."

So, there's no real evidence to prove Tornado Alley is shifting to the east because scientists don't have a lot of data to compare it to. Outside of the SyFy network, it doesn't appear any researchers studying whether a "Sharknado" or even a "Snownado" are possible.