MADISON – On the evening of April 14, Madison’s east side was pelted with balls of hail.
Not the typical small pellets, but some as big as softballs or baseballs, which shattered windshields, broke off chunks of siding on homes and broke off branches of freshly blooming trees. Tornado sirens blared across the neighborhoods, not because of an impending tornado, but due to hail so sizable it could injure anyone outside.
As the hail stopped, and the rain let up, residents surveyed the damage. Some strapped tarps across broken car windows, while others filed insurance claims. People picked up globes of ice and took photos for social media.
The storm that ripped through Wisconsin, causing not only damaging hail, but several tornadoes, was unseasonably early, something that could become more common as the earth’s climate warms.
Steve Vavrus, Wisconsin’s state climatologist, said that parsing out this storm’s relation to climate change at this point is difficult, but it was likely helped along by conditions not typically seen in April, such as an 80-degree day and high levels of humidity.
Hail is created when strong updrafts of air are pushed up into the colder atmosphere, freezing water droplets and pushing them around, making the droplets bigger and bigger. Eventually, those hailstones get too heavy and fall back down to earth.
Vavrus can say that a warmer climate is causing these conditions, allowing hail to take form, especially at times when storms like the one on April 14 aren’t expected.
“Climate change is making things less predictable,” he said. “We’re getting severe storms out of season more than we used to.”
Typically, tornadoes and hailstorms are seen during the later summer months, not in the early spring. Coupled with tornadoes seen in February in recent years, this April storm is out of the ordinary.
In addition to storms producing unseasonable conditions, climate change is also evident in the amount of rain Wisconsin is seeing this spring, Vavrus said.
So far this year, Green Bay has seen a record-breaking amount of rain for April, and Madison and Milwaukee are on their way to new records for rainfall totals.
“The trend toward warmer, toward wetter springs and wetter winters is a sign of climate change. That’s what climate models have been forecasting for a long time,” he said. “We see it in observational records going back to the middle 20th century and even before.”
A 2024 study by Northern Illinois University said climate change is going to make hail-producing storms like this one more common.
The study, which utilized models of hail-producing storms, showed that golf-balled sized hail or larger is going to be seen much more often in coming years, due to the increase in atmospheric instability.
“In our study, the largest hailstones are found to increase by 15% to 75%, dependent on greenhouse gas emissions,” NIU Atmospheric Science Professor Victor Gensini said in an article about the study.
The study found that the Midwest, along with the Ohio Valley and the Northeast, will experience an increase in the number of storms producing large hail.
Hail in Madison was large, but not record-breaking
Some of the hailstones reported near Maple Bluff in Madison measured in about 4 inches in diameter, according to Weather Channel Meteorologist Jonathan Erdman in a post on X.
The last time hail that large occurred in Dane County was in July 1960, more than 65 years ago.
But that isn’t the largest hail ever seen in Wisconsin.
That record is held by a 5.7-inch stone recorded near Wausau in May 1921. And in more recent history, a 5.5-inch hailstone was recorded in Port Edwards in 2007.
According to data from the Wisconsin State Climatology Office, the occurrence of large hail has indeed increased over the last 70 years, and has largely been reported in southern and central areas of Wisconsin and around larger metro areas.
Expect the unexpected when it comes to storms
As Wisconsin’s unseasonable weather continues, Vavrus said the most important thing is to remain alert and ready to seek shelter if needed, no matter the season.
“It’s easy to think, ‘Oh, it’s February, we can’t have tornadoes,’ or ‘Oh, it’s only April, we can’t really have major storms or hail in April,'” he said. “But yes, we can. You can’t just think in terms of a calendar. You need to think what the weather conditions are on that day.”
Vavrus said that because weather forecasting has gotten better, the public can be alerted earlier. And it’s important to pay attention to those alerts, and take them seriously.
“This is where we need to adapt to changing climate and not just base our expectations on the past,” he said.
Laura Schulte can be reached at leschulte@jrn.com and on X @SchulteLaura.
This article originally appeared on Milwaukee Journal Sentinel: Hailstorms in April? Warmer temps lead to unseasonably early storms
Reporting by Laura Schulte, Milwaukee Journal Sentinel / Milwaukee Journal Sentinel
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