Figure 1 depicts the surface observations at 8:00 am EDT, which shows a cold front moving across the Great Lakes, which brought southerly winds to Massachusetts. Pre-frontal thunderstorms likely initiated in the morning hours of July 5th, which ultimately led to this tornado.

The New Salem, MA F1 tornado of July 5, 1984 impacted Franklin County in Massachusetts. According to NOAA (2019), the F1 tornado caused no fatalities or injuries, but caused $25 thousand dollars in property damage. The tornado touched down near South Main Road at 3:30 pm EDT. The tornado travelled for 2 miles and had a maximum width of 80 yards.
Sources
NOAA Central Library. (2020). U.S. Daily Weather Maps. Thursday July 5, 1984 [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/