A powerful tornado developed, striking regions of St. Louis and London, Kentucky on May 16th, 2025, marking a particularly violent and deadly day for tornado activity.
Reports from across the US indicate a higher than average number of tornadoes this year – with over 960 recorded, according to the National Weather Service’s latest count as of May 22nd.
This figure is significantly above the 15-year average of approximately 660 tornadoes during the same timeframe, resembling the activity level seen in 2024. It is the second most active year recorded.
I am an atmospheric scientist, adept at examining natural disasters. What stands out so far in 2025 is not just the surge in tornado counts but the widespread nature, affecting almost every area east of the Rockies, indicating an all-year-round tornado season.
What contributed to the high activity in 2025?
The surge in tornadoes during 2025 can be attributed to specific weather patterns in March, which saw a record-breaking number of tornado events, with 299 tornadoes reported—far exceeding the monthly average of 80 over the last 30 years.
The March statistics were significantly influenced by two major tornado outbreaks, which saw around 115 tornadoes sweep through more than 12 states from March 14th to 16th, ranging from Arkansas to Pennsylvania, alongside another outbreak that produced 145 tornadoes hitting from March 31st to April 1st, primarily in Arkansas, Iowa, and further east. The final count for 2025’s tornadoes is still pending preliminary analysis.
Meteorologists are yet to pinpoint why March was so active, although several factors conducive to tornado formation were present.
However, as April and May arrived, those key factors diminished. The weak La Niña phase concluded, and Gulf sea temperatures returned to near normal.
Both April and May did experience tornado outbreaks, but following the significant occurrence from March 31 to April 1, most preliminary reports have remained close to the average, and changes in numbers remain possible.
What was notable in April and May is the persistence of conditions. The jet stream remained unstable, enhancing the typical ebb and flow of low-pressure weather systems, which often combined with sunny, high-pressure conditions. In some instances, tornadoes were reported in Colorado, Minnesota, Delaware, Florida, and nearly every state in between.
In years with fewer tornadoes, there are often more prolonged periods characterized by sunny, high-pressure systems residing in central US regions, but the spring of 2025 did not experience any such mild periods.
Shifts in Tornado Alleys
The geographical distribution of tornadoes is also significant. Although tornado activity in 2025 has been widespread, affected areas are beginning to include the Lower and central Mississippi Valley, which stretches from Illinois to Mississippi.
The traditional Tornado Alley normally extends from Texas to Nebraska and even further east in general. The peak season for tornadoes continues to be from April to May in the Mississippi Valley, yet activity is now more likely to be found along the eastern fringes rather than at the central core. The normal seasonal tornado cycle shifts southwest from near the Gulf Coast during winter to the Upper Midwest in summer, culminating in the Great Plains by the height of summer.
In recent decades, tornado occurrences in the US have undergone significant changes in three key ways: shifting eastward during the year, demonstrating a notable pattern of large outbreaks.
Winter tornadoes are becoming more frequent in the southeastern and eastern US regions, now collectively known as Dixie Alley, with increased activity noted particularly in areas like Kentucky, Illinois, and Indiana.
Conversely, there have been some stable patterns, including a decline in tornado frequency during their historically “traditional” peak seasons, namely the spring and summer months primarily across the Great Plains.
It’s noteworthy that the US has seen an overall decrease in actual tornado occurrences over the past several decades, particularly in terms of strong storms classified as EF2 or higher. While there are fewer tornado days overall, the occurrence of stronger tornadoes has been on the rise, indicating a potential stability in trends over the last decade.
Increased fatality risk from tornadoes
The eastward shift in tornado activity raises concerns regarding the potential for increased fatalities.
Tornadoes in the southeastern US have a higher likelihood of striking at night, when individuals are often asleep and unable to respond effectively, which can exacerbate the dangers of these events. Tragically, many victims of the Kentucky tornado occurred shortly after 11 PM, with over 65 years of age or older.
The increase in winter tornado occurrences leaves communities more vulnerable, as residents may not be on high alert during these times. While tornado detection and prediction technologies are improving, which have saved numerous lives over the past half-century, their efficacy is contingent on timely communication of warnings.
This eastward trend in tornado activity aligns with predictions regarding the impacts of global warming on severe thunderstorms as the climate warms. Nevertheless, researchers remain uncertain whether the overall downturn in tornado occurrences can be attributed to warming or if this trend will persist in the future. Conducting a field campaign aimed at understanding tornado formation could enhance our comprehension of these dynamics.
Keep in mind, it takes just one
For the sake of safety, it’s crucial not to view spring solely as tornado season.
The region considered the tornado alley stretches east of the Rockies and west of the Appalachians for a considerable duration throughout the year. The farther south one lives, the length of tornado season generally increases.
We often highlight hurricanes annually, but it’s vital to adapt this mindset for tornadoes: it only takes one to impact your life and your community drastically. Residents in areas like London, Kentucky; St. Louis; Plevna and Grinnell, Kansas; and McNairy County, Tennessee can attest to this.
Follow local meteorologists to stay informed about tornado risks in your area, and if you hear a tornado siren or receive a warning, promptly seek shelter. Tornadoes can form rapidly, and taking swift action can save lives.
This revised article has been republished from The Conversation under a Creative Commons license. For the original piece, please read the original article.
Source: www.livescience.com