The National Weather Service says a thunderstorm microburst up to 100 miles an hour likely caused the extensive tree damage this week in the western Massachusetts town of Wilbraham.
The weather service said Thursday the strong downdraft hit along a two-mile path Tuesday afternoon. It averaged about 250 yards wide, but spread 600 yards at its widest. Moderate tree damage extended about half a mile.
Tornado warnings were issued Tuesday for part of western and central Massachusetts, but the weather service said after assessing damage that no tornadoes touched down.
The storms downed trees and power lines in several communities. A motorcyclist died in Hinsdale when he struck a fallen tree entangled in power lines.
Tuesday's bad weather rattled nerves after June 1 tornadoes in the area killed three people and caused millions in damage.
This program aired on July 28, 2011. The audio for this program is not available.