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Death by 1,000 Paper Cuts

The year 2024 has etched its name into the annals of extreme weather history in the United States, marked by a staggering surge in tornado activity. From January to November, the National Oceanic and Atmospheric Administration (NOAA) documented an extraordinary 1,762 tornadoes, the highest annual count in over a decade. This unprecedented year of twisters has left meteorologists and researchers scrambling to understand the underlying causes.

A Year of Tornado Outbreaks

Unlike other years defined by a few catastrophic tornadoes, 2024’s hallmark was its sheer volume of tornado activity, scattered throughout the months. “It was like death by 1,000 paper cuts,” said Victor Gensini, a meteorology professor at Northern Illinois University. The absence of back-to-back, record-breaking outbreaks belied the cumulative impact of these events, which collectively made 2024 a landmark year for severe weather.

While no single month stood out as historically exceptional, the consistent occurrence of tornadoes compounded into a significant weather story. Among these, the twisters spawned by Hurricane Milton in October proved especially destructive, standing out as an anomaly even in an already chaotic year.

The Economic Toll of Tornadoes in 2024

Tornado outbreaks in 2024 ranked among the year’s most financially devastating weather events. NOAA recorded 24 climate and weather disasters causing damages of at least $1 billion each. Of these, six were tornado outbreaks. For instance, a three-day storm cluster in July produced more than 79 tornadoes across states like Illinois, Indiana, Minnesota, Pennsylvania, and New York, causing $2.4 billion in damages.

One particularly catastrophic event occurred in May, when a massive EF-4 tornado cut a 44-mile swath across southeastern Iowa, claiming five lives and leaving $4.9 billion in damages. This tornado was part of a larger outbreak that included more than a dozen twisters ripping through the state in a single day.

While the death toll of 52 recorded tornado-related fatalities through November is relatively low compared to historic years, the widespread destruction left in their wake speaks to the immense power of these storms. In comparison, the single deadliest tornado in U.S. history, an EF-5 in 1925, claimed 695 lives.

Tornado Classifications and Their Impact

Tornadoes are ranked using the Enhanced Fujita (EF) scale, which measures their intensity based on wind speeds and potential for damage. EF-0 and EF-1 tornadoes, the weakest, have winds up to 110 mph, typically causing minor damage. In contrast, EF-5 tornadoes, with winds exceeding 200 mph, leave catastrophic destruction in their paths.

The EF-4 tornado that ravaged Iowa in May was among the deadliest and most destructive of the year. It obliterated the town of Greenfield, flipping vehicles and ripping homes from their foundations. Elsewhere, a late May outbreak produced more than 110 tornadoes, including an EF-3 in Texas, resulting in $3.4 billion in damages.

Surprises in Tornado Activity

Some tornado events in 2024 defied expectations. In November, a rare tornado touched down north of Santa Cruz, California, marking the first time the National Weather Service issued a tornado warning for San Francisco. The EF-1 tornado, with peak winds of 90 mph, injured five people and added to the year’s list of surprises.

Perhaps the most notable anomaly of 2024 was the surge in strong tornadoes linked to hurricanes. Hurricane Milton, which made landfall in Florida in October, produced dozens of tornadoes, including several of EF-3 intensity. This phenomenon, while not unheard of, is rare. Historically, less than 1% of tornadoes spawned by tropical systems reach EF-3 strength or higher.

Victor Gensini highlighted the exceptional nature of Hurricane Milton’s twisters:

•  “Those tornadoes rivalled what you’d expect in Tornado Alley — Texas, Oklahoma, Nebraska. It’s highly unusual to see such strong tornadoes associated with hurricanes.”

The Climate Change Question

One of the pressing questions arising from 2024’s tornado activity is the potential link to climate change. Unlike heatwaves or wildfires, which have direct correlations with rising temperatures, the relationship between global warming and tornadoes remains unclear.

Tornadoes require atmospheric instability and vertical wind shear — a combination of temperature contrasts and changing wind directions at different altitudes. While research suggests global warming may heighten atmospheric instability, it could simultaneously weaken vertical wind shear, potentially suppressing tornado formation.

A study published earlier in 2024 indicated that tornadic storms could increase by up to 299% by mid-century if fossil fuel emissions persist at current levels. However, pinpointing the influence of climate change on individual tornado events remains a complex challenge.

• “We know that greater instability and warmer temperatures could promote more tornadoes,” Gensini said. “But determining the role of climate change in any single tornado event is still very difficult.”

Looking Ahead

Although the last quarter of 2024 has been relatively quiet for tornadoes, the potential for late-season outbreaks remains. Historically, strong tornadoes have occurred in December during the cooler months. Severe weather forecasts for the South and Gulf Coast regions suggest the possibility of more tornadoes before the year concludes.

As scientists continue to study 2024’s tornado activity, the year serves as a reminder of the growing challenges posed by extreme weather. The events of this year underscore the need for improved forecasting, infrastructure resilience, and a deeper understanding of the connections between climate change and severe weather.

The story of 2024’s tornadoes is one of nature’s unpredictability and power, leaving behind a trail of questions, damages, and lessons for the future.