What caused 78 mph wind speeds in Bloomington last night?

A powerful storm struck Bloomington on Tuesday afternoon, toppling trees and utility poles and leaving tens of thousands without power. 

At its peak, the storm’s winds hit 78 miles per hour, National Weather Service meteorologist Andrew White said. Wind speeds over 75 miles per hour are classified as “hurricane force,” capable of pushing moving vehicles off the highway, overturning mobile homes and peeling off roofs. The average wind speed during Tuesday afternoon's storm was 60-70 mph, powerful enough to uproot trees and cause the widespread damage seen in Bloomington today. 

White said the storm was an MCS, or mesoscale convective system, characterized by clusters of individual thunderstorms. A disturbance in the upper atmospheric flow combined with hot, humid air to form the MCS, which moved from Illinois to Terre Haute yesterday before hitting the Bloomington area.

The storm was common for the region, White said, and Indiana typically experiences it a few times a year. However, the storm demonstrated stronger winds and lasted longer.

“This one was a little more organized,” he said. 

The NWS Storm Prediction Center shows a marginal risk of continued severe weather today, meaning isolated thunderstorms are possible but would likely be lower in intensity and duration.

Reach Marissa Meador at mmeador@gannett.com.