Massachusetts isn't really the sort of place you would expect to have strong tornadoes, but around 7pm on Memorial Day of 1995 an F3-F4 tornado tore through Great Barrington, MA, flattening the Fairgrounds, killing 3 people, and injuring 12.
This tornado inspired research into the relationship between tornadogenesis and local terrain. Meteorologists have found that the north-south orientation of the Hudson and Housatonic valleys increase lower level wind shear when the surface wind is southerly, increasing the likelihood of tornadoes forming in a local "Hot Spot" extending from Hudson valley, NY to Berkshire County, MA and Litchfield County, CT. (Local Tornado Hot Spot)
Radar images showing the tornado formation:
SUNY Albany Studies the '95 Tornado
Research Paper on this, and other New England tornadoes:
Terrain Influenced Tornadogenesis in the Northeastern United States: An Examination of the 29 May 1995 Great Barrington, MA, Tornado
Official Tornado Stats:
NCDC Event Details
A couple pictures of the damage:
