Figure 1 depicts the surface observations at 8:00 am EDT, which shows a cold front moving across southern Ontario. This front eventually made it to Massachusetts, where it triggered several supercell thunderstorms, which ultimately led to this tornado.
The East Longmeadow, MA F1 tornado of August 10, 1979 impacted Hampden County in Massachusetts. According to NOAA (2019), the F1 tornado caused no fatalities, but injured 1 person and caused $25 thousand dollars in property damage. The tornado touched down near Grove Ave at 4:30 pm EDT. The tornado travelled for 0.6 miles and had a maximum width of 30 yards.
Sources
NOAA Central Library. (2020). U.S. Daily Weather Maps. Friday August 10, 1979 [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/