Figure 1 depicts the surface observations at 8:00 am EDT, which shows a cold front across the Great Lakes. This front eventually moved east toward Massachusetts and triggered thunderstorms throughout the day, which ultimately led to this tornado.

The Tatham, MA F2 tornado of July 25, 1975 impacted Hampden County in Massachusetts. According to NOAA (2019), the F2 tornado caused no fatalities or injuries, but caused $25 thousand dollars in property damage. The tornado touched down near Almon Ave at 12:04 am EDT. The tornado travelled for 0.3 miles and had a maximum width of 33 yards.
Sources
NOAA Central Library. (2019). U.S. Daily Weather Maps. Thursday July 24, 1975 [PDF]. Retrieved from https://library.noaa.gov/Collections/Digital-Collections/US-Daily-Weather-Maps
NOAA National Centers for Environmental Information (2019). Storm Events Database. Retrieved from: https://www.ncdc.noaa.gov/stormevents/