Are tornadoes increasing in frequency in Vermont?

Vermont has had a spate of severe weather recently with a few confirmed tornadoes. Are twisters becoming a more common hazard in the Green Mountain state? The answer might surprise you.

A July 19 thunderstorm spawned at least a couple twisters with ones in Addison and Waltham confirmed. The Addison cyclone had peak winds of 90 miles per hour, putting it at an EF-1 tornado on the Enhanced Fujita scale which rates tornado intensity on a scale of 0 to 5. The Waltham tornado, just several miles away, occurred a few minutes later. Winds of 70 miles per hour designated it an EF-0 tornado.

On July 21, a tornado warning was issued for a couple northeastern counties including the towns of Canaan, Newport, Orleans and Barton. Tornado warnings are issued when a tornado has been spotted or indicated by weather radar; in this case the radar caught the tornado. A tornado watch, on the other hand, means conditions indicate a tornado is possible.

Are tornadoes becoming worse in Vermont?

While the area considered to be "tornado alley" has shifted eastward, it hasn't approached Vermont and we are well out of the hot zones.

While a few tornadoes in a short period may seem like a lot, the numbers over time do not show an increase in tornadic activity in Vermont.

The National Oceanic and Atmospheric Administration (NOAA) has been collecting tornado data since 1950.

In that time 47 tornadoes were recorded and about half of the years had one to two tornadoes. The three we've seen recently is just above average. Vermont saw three tornadoes in 1961 and one year later, 1962, the state had the most tornadoes recorded in one year at five.

It could seem like tornadoes are increasing in frequency because we've had several after a six year gap where no tornadoes were recorded from 2013 through 2018 and, again, there were none in 2020. However, those gaps have become larger over time.

There were a couple of one year gaps of no tornadoes in the 1950s, a one year gap and a two-year gap in the 1960s.

There largest gap occurred between the 1970s and 1980s where there were no twisters for eight years, from 1974 through 1981.

Another two-year gap in the 1980s, then the 1990s saw several gaps − three years going into the decade, four in the middle and three at the end.

There were tornadoes in 2002 and 2003 but not again until 2008. From 2008 to 2012 there were either one or two tornadoes recorded each year.

The severity hasn't seemed to get worse, either. The most intense tornadoes in Vermont have been rated an EF-2 for peak winds of 113 to 157 miles per hour. Of the 14 that have been that intense, seven of them occurred in the 1960s, three were in the 1950s and there have been just one in the 1970s, 1980s, 1990s and early 2000s.

The last EF-2 was recorded on June 5, 2002, just northeast of Wilmington where it mostly destroyed a house.

Fortunately, there have been no deaths associated with Vermont tornadoes from the last 70 years. Property and crop damage costs have been estimated at about $5.6 million over the span of time up until April 2022.

What is a tornado? Everything you need to know about these violent storms

Contact April Barton at abarton@freepressmedia.com or 802-660-1854. Follow her on Twitter @aprildbarton.

This article originally appeared on Burlington Free Press: Are tornadoes becoming more common in Vermont? What numbers show.