Is it unusual to have several tornadoes a year in Massachusetts?

BOSTON – It seems like this has been a very busy summer for not only rainfall and flooding but tornadoes as well. Is it unusual to have this many tornadoes here in Massachusetts? What’s going on?

July brought a lot of wet weather with over 10″ of rain in Boston, severe weather, and several tornado warnings across the area. The National Weather Service issued their first tornado watch in our area in over a year!

On July 16th, an EF-0 tornado with estimated winds of 80 mph touched down briefly in North Brookfield damaging trees in the area. It traveled about two miles. That was the first of two tornadoes to touch down in about two weeks.

On Saturday July 29th, an EF-1 tornado with estimated maximum winds of 105 mph touched down in Foxboro near Easton and Mansfield traveling about 300 yards.

Both were “typical” New England type twisters, short-lived, wrapped with rain and relatively weak, and thankfully no injuries were reported.

Historically… Massachusetts averages two tornadoes a year with July being the most active month for twisters.

So, getting the number of tornadoes we’ve seen so far… is not all that uncommon. However, having the right atmospheric conditions last month did help produce the twisters.

July had plenty of days with warm, moist air. We also had a lot of instability and available energy, a parameter we look for that can be a good signal of how strong a storm can get.

There were also many times wind shear was prevalent, which means the wind changed direction and speed the higher you travel in the atmosphere. Also, having a strong jet which can steer individual storms and can create a strong upward motion helping to produce severe storms that ultimately form tornadoes. 

We had a lot of instances with the right conditions coming together… but there have been plenty of summers when they haven’t. Just last year we had zero tornadoes… but the year before that six… those, however, came with tropical systems. The number of tornadoes varies through the years. We had three tornadoes each in 2020 and 2019 and seven back in 2018!

Despite all the technological improvements in recent years, most of our tornadoes in New England remain hard to detect on Doppler Radar. Many times, they form or “spin-up” so quickly, by the time the warning is issued, they may already have lifted.

So bottom line, we’ve seen a few weak tornadoes which is common for this area, and unfortunately, we can’t let our guard down yet, as there is plenty more summer to go. It’s a good reminder to taking warnings seriously and have a backup plan indoors on days where severe weather is possible.  

If you have a question you’d like us to look into, please email questioneverything@cbsboston.com.