Editor's note: Scott Stransky is a Manager and Principal Scientist at catastrophe modeling firm AIR Worldwide.

Losses from severe thunderstorms have accounted for approximately one half of all U.S. catastrophic insured losses since 1990, according to Property Claim Services (PCS). Because of the relative frequency of thunderstorms, as compared to hurricanes or damaging earthquakes, many insurance companies believe their historical loss data is sufficient to capture the risk from this peril.

However, severe thunderstorms can often result in unexpected losses and highly volatile financial outcomes because of the localized nature of the peril and the growing number and value of exposures in harm's way.