A severe thunderstorm outbreak from April 13 to 15 cut through a wide corridor from the Plains to the Lower Great Lakes, with Guy Carpenter warning that the event will drive significant hail and wind-related insurance losses – adding fresh pressure to what reinsurance markets are increasingly treating as a primary risk category.
The outbreak produced 46 tornadoes and 785 hail reports across 21 National Weather Service forecast offices. The hardest-hit states included Kansas, Minnesota, Iowa, Wisconsin, and Michigan, with an EF2 tornado causing injuries in and near Ottawa, Kansas, and a second EF2 tracking through Miami County.
In Minnesota, hailstones measuring up to 3.5 inches in diameter were recorded in Lake Crystal. By the system's end, more than 50,000 homes and businesses across Illinois, Indiana, Missouri, and Oklahoma had lost power.
Guy Carpenter said losses are expected to be driven primarily by hail and straight-line winds, with tornado damage remaining more localized. Hail cores at or above 2.5 inches raise the likelihood of roof replacements and elevated auto losses, with early indicators pointing to meaningful claims activity in higher-exposure areas.
The event lands at a delicate moment for the reinsurance sector. Moody's Ratings has noted that reinsurers are holding firm on elevated attachment points set after the post-2023 market reset, leaving primary carriers to retain a greater share of secondary-peril losses and the earnings volatility that comes with them.
Cotality, in its 2026 severe convective storm report, framed the stakes plainly: the question of whether a single hailstorm can rival the financial impact of a Category 4 hurricane, it said, "is no longer theoretical."
The April event arrives against a backdrop of growing industry alarm – one that Acrisure Re documented in research published in March. That report found that insured losses from severe convective storms reached nearly $200 billion between 2020 and 2024, roughly 150% higher than the prior five-year period.
The firm attributed the escalation to structural exposure factors: population growth in hazard-prone regions, rising property values, and higher construction and repair costs, rather than meteorological shifts alone. Hail, it noted, accounts for an estimated 50% to 80% of total severe convective storm losses.
The same Acrisure Re report also highlighted a longer-running geographic shift. Supported by NOAA data, the geographic center of US tornado activity has moved roughly 500 miles eastward since 1980.
What researchers now call "Dixie Alley" encompasses Nashville, Atlanta, Charlotte, and Raleigh – cities with denser populations, faster-moving storm systems, and housing stock less engineered for high-wind events than Great Plains construction.
For carriers active across the Southeast, the trend is already reshaping underwriting exposure in markets where historical loss data offers limited forward guidance.
Guy Carpenter noted that a brief pause in thunderstorm activity is expected this week before conditions turn more active in the final days of April and into early May.
