May finishing as second-most active for severe weather with over 6,100 storm reports

The deadliest tornado occurred in Cooke County, Texas, where seven people were reported to have lost their lives. According to the National Weather Service's Storm Prediction Center, 36 people have been killed by tornadoes in 2024, with Texas reporting the most fatalities.

A spring severe weather season under a diminishing El Niño helped propel this month to become among the most active Mays for tornadoes, hail and damaging winds.

Through the first 30 days of May, the National Weather Service's Storm Prediction Center received over 6,100 reports of severe weather, including 475 tornadoes. 

 So far, it's the second-most storm reports in May since data began in 2004, trailing 2011's 6,763, according to the SPC.

An average May only produces somewhere in the neighborhood of 275-300 tornadoes, meaning tornadic activity was some 70% above average.

Most of the tornadoes occurred during outbreaks from May 6-10, May 19-24 and May 25-27, which accounted for at least 300 of the initial reports.


Iowa leads the country with the most tornadic activity so far this year, which is a bit unusual for the Hawkeye State.

Through the Memorial Day weekend, National Weather Service offices had reported 98 tornadoes, with Texas, Nebraska, Missouri and Oklahoma finishing out the top five.

The deadliest tornado occurred in Cooke County, Texas, where seven people were reported to have lost their lives during a nighttime twister.

According to studies, tornadoes that occur at night are more than twice as likely to result in deaths than those that happen during the day. Often, these tornadoes cannot be spotted before it is too late or occur when people are sleeping.

In addition to tornadoes, the FOX Forecast Center tracked at least three derechos during May, which produced hurricane-force winds across communities in Texas, the Plains and the Midwest.

A derecho that struck Houston resulted in at least eight deaths and over 1 million power outages in the metro on May 16.

Some of the damage was comparable to Hurricane Alicia, which struck the region in August 1983.


What caused the uptick in activity?

Many forecasters believe a weakening El Niño played a significant role in the uptick of severe thunderstorm activity during the late spring.

The spring season, which consists of March, April and May, is typically the busiest period for severe weather as the jet stream allows plenty of warm moisture to stream northward and aids in the instability needed for thunderstorms.

During episodes of El Niño, severe weather outbreaks are usually less common as the jet stream does not promote clashes of air masses.

Other statuses of the El Niño-Southern Oscillation, or what is commonly referred to as the ENSO, promote upticks in severe weather activity compared to the El Niño state.

The weak state of the El Niño to even neutral conditions in the Pacific allowed for around 1,000 reports of tornadoes in the U.S. through the first five months of the year.

The country averages around 1,300 tornadoes annually, meaning the country is already well on its way to seeing at least an average year for tornadic activity.