A small tornado touched down in southern New Hampshire on Sunday, NWS confirms - The Boston Globe (2024)

The National Weather Service confirmed Monday that a small tornado touched down in Dublin, N.H., on Sunday afternoon, as multiple rounds of severe thunderstorms moved through New England. The weak EF-1 tornado, the second-lowest rating for twisters, was reported at 5:09 p.m. It had peak winds of 90 miles per hour and traveled nearly 4 miles before dissipating four minutes later.

The tornado’s path was about 40 yards wide. No one was injured in the tornado, according to officials.

“There was lots of rotation with that system that pushed through southern New Hampshire,” said Jon Palmer, a meteorologist with the weather service’s office in Gray, Maine, which covers New Hampshire.

A survey team from the office identified “dozens of snapped white pine trees with uprooted maples and oaks also noted ... as well as a truck being briefly lifted and moved along the ground,” the weather service said, adding that no “significant” structural damage to homes and buildings was observed.

Palmer said the survey crew was continuing to assess on-the-ground damage reports, going from town to town looking for other tornado “touchdown points.”

“The storm survey team is going to Keene, Manchester, and the seacoast area to see any potential touchdown locations,” Palmer noted.

About 47 miles east of Dublin, in Manchester, N.H., a funnel cloud was spotted near Interstate 93 around 6 p.m. Sunday, according to witnesses and trained weather spotters.

An EF-1 tornado is the second lowest rating on the Enhanced Fujita Scale, with an EF-0 being the weakest. EF-1 tornadoes have sustained winds of 86 to 110 miles per hour. Both EF-0 and EF-1 tornadoes are considered “weak” twisters.

Sunday saw the first round of tornadic weather of the year, with eight tornado warnings issued as a cluster of severe thunderstorms developed across parts of New Hampshire, Vermont, and Connecticut — a rare occurrence for a region that only sees about one or two twisters a year, although there are exceptions. The last time New England saw tornadoes before Sunday was August 2023, when a tornado was confirmed in early August and then a cluster of twisters was confirmed two weeks later.

The main difference between Sunday’s severe storms and previous thunderstorm events this year was the decent amount of change in both wind direction and height — basically as you go up into the atmosphere from the surface, the wind would twist, allowing for rotation within storms that can spawn tornadoes.

How do tornadoes form?

The wind shear — the change in wind speed and/or direction over a certain distance — is the main element, outside of instability in the atmosphere. With varying wind directions happening all at once within a storm, a tube of rotating air may materialize.

If the updraft of the storm is strong enough, it will tilt the rotating tube vertically, leading to tornado formation.

Is it rare for New England to see tornado activity?

It is uncommon for New England to see tornadoes since the region only sees about one tornado each year. For comparison, Texas averages 137 tornadoes per year, the most of any state in the country.

The geography of New England has a lot to do with this. New England’s topography is quite different from the classic ”Tornado Alley” region down South and doesn’t match the usual tornado-producing environment.

Typically, tornadoes need drastically different air masses to meet to have the potential to develop — this means cooler, dry air interacting with warmer, moist air. The region most conducive to developing tornadoes is in the Great Plains, where there are big differences in air masses coming from Canada and from the Gulf of Mexico.

Usually, with New England abutting the coast and temperature contrast less extensive, it’s harder for a tornado-producing atmosphere to come together, although not impossible. Think of the Great Barrington EF-4 tornado in 1995 and the deadly F-4 Worcester tornado in 1953, in which 94 people died and hundreds more injured. Or a more recent example: The tornado that struck downtown Springfield in 2011, killing three people.

Plain and simple, conditions have to be right. There is scientific evidence that more energy is becoming available across New England to spark more severe thunderstorms during the summertime, essentially human-induced climate change driving temperatures up to an increasing trend over the last 20 years — and with warmer temperatures comes more moisture that results in increase instability.

Below is a graph detailing severe thunderstorm and tornado watches issued for Massachusetts since 1997, compared to the national count. Last summer there were 12 watches issued for parts of Massachusetts. So far, in 2024, there have been three.

Ken Mahan can be reached at ken.mahan@globe.com. Follow him on Instagram @kenmahantheweatherman.