Initial insured loss estimates suggest that losses from the March 10-12 US severe convective storm (SCS) outbreak will land in the low to mid-single-digit billions of dollars, with total economic losses poised to be 20-25% higher, according to reinsurance broker Gallagher Re.
The March 10-12 SCS outbreak hit more than a dozen states across central and eastern parts of the US, bringing violent and damaging tornadoes, potentially record-setting hail, and straight-line wind damage.
“This week’s outbreak brought widespread impacts across several central and eastern US states. While deadly tornadoes have driven most media coverage, we again witnessed considerable (and record-breaking) hail in many communities that drive widespread damage. Parts of the major metro areas of Chicago (IL), Kansas City (MO), and Oklahoma City (OK) were affected by baseball-sized hail – or larger,” said Steve Bowen, Chief Science Officer at Gallagher Re.
According to Gallagher Re, the outbreak is likely to become the most impactful and expensive US SCS event so far in 2026, as SCS-related damage costs with aggregated insured losses from January and February events landed below $1 billion.
March is known as the start of the peak SCS season in the US. “The peak months for overall SCS activity and observed losses are March, April, May, and June. Since 2010, those four months have accounted for at least 72% (USD390 billion) of US SCS insured losses. On an annual basis, the US has now seen three consecutive years of minimal USD50 billion in SCS-related insured losses,” explains Gallagher Re.
In fact, on an annual basis, Gallagher Re finds that, at $542 billion, SCS has now far surpassed the tropical cyclone peril ($367 billion) on an aggregate basis as the costliest for insurers since 2010.
The global rise in SCS losses was discussed recently by re/insurance broker Aon, who also warns that the March outbreak in the US could drive insured losses in the low billions of dollars.
“Total economic and insured losses over the past week may reach the low to mid-single digit billions USD,” said Aon on the SCS outbreak in its March 13 Weekly Cat Report.
