What the heck was that tornado watch in Vermont? We have seen low-grade twisters before.

Vermont is several hundred miles from the eastern edge of "Tornado Alley" but twisters do occasionally touch down in the Green Mountain State.

While infrequent here, at least 46 tornadoes have struck Vermont soil since 1950, when the National Oceanic and Atmospheric Administration began cataloging the severe weather events, and about half of the state was on a tornado watch as weather related to Tropical Storm Isaias moved through the state.

More:Tropical Storm Isaias douses Vermont's hot, dry summer — for now

Just last year, an EF1 tornado, the second lowest rating of the six-level scale meteorologists use to classify storms, hit the town of Windham on Aug. 21 with wind speeds between 105 and 110 mph. A National Weather Service storm survey team discovered a 350-yard swath of almost continuous damage that stretched 3/4 of a mile, damaging homes, uprooting trees and tossing outdoor furniture and debris hundreds of yards.

Roughly 77% of the 1,200 or so tornadoes the US sees each year are like the Windham storm. Only about 5% of them reach EF3 or above, capable of causing wholesale devastation with winds surpassing 200 mph, according to NOAA.

Here's a look at five of Vermont's most significant tornadoes over the years: 

July 9, 1962

A pair of EF2 funnels struck Windsor County shortly after 9 a.m.

The first tore a 10-mile path from Chester to Weathersfield, through North Springfield. The second, touching down about half an hour later, tracked from Springfield across the Connecticut River and into Charlestown, New Hampshire.

It was the busiest day of a summer that set a record with five tornadoes in Vermont.

Aug. 3, 1970

A freak storm rolled across Lake Champlain shortly before 5 p.m., producing an EF2 tornado that injured seven people in St. Albans Town.

"I looked out and it was just like smoke coming from the lake, like rolling smoke, like the lake was on fire," one resident told the Free Press. 

Near the lake, the twister overturned a trailer with three adults and eight children inside. Then it tracked over land for more than 2 miles before wrecking the Gamache farmhouse and collapsing a newly reconstructed barn. 

Aug. 8, 1983

The storm that caused an EF2 to strike Colchester the evening of Aug. 8, 1983 caused $2.5 million in damage. The funnel cloud confirmed a day later by the weather service to have touched down near Vermont 2A came with hail and heavy winds. 

On Starr Farm Road in Burlington, the powerful storm knocked a hefty pine tree onto the second floor of the Dowe family's camp — right onto the bed where young Leslie Dowe had been lying until her parents, Tom and Betty Ann, worried about the weather, called her downstairs, according to the Aug. 10 edition of the Free Press.

May 31, 1998 

A tornado that crossed Saratoga and Rensselaer counties in New York hit Bennington County as an EF2 but quickly weakened to Category 1 storm, according to NOAA. It followed Vermont 67 from the state line into North Bennington and Shaftsbury, producing extensive damage to homes in the area. The event thrashed or felled many trees on the Bennington College campus, knocked out power for roughly 8,000 customers — some for as many as three days. More than $600,000 in damage resulted.

July 21, 2003

The weather system that created a long-lived tornado in the Hudson Valley of New York spawned a second in Bennington County that then struck ground in Pownal and proceeded to head north for 25 miles, making it Vermont's longest.

The path was up to 150 yards wide, according to NOAA, and stretched into the western edge of Windham County where it caused significant damage in the Green Mountain State Forest. Trees fell on multiple houses and a Bennington steakhouse was forced to close for several days due to storm damage. At the height of the storm, more than 2,000 customers lost power in Vermont.

Tornadoes in the region

Mercifully, no deaths have been attributed to any Vermont tornado in the last 70 years, either directly or indirectly, based on data compiled by NOAA. Neighboring states haven't been so lucky.

As recently as 2011, an EF3 storm in western Massachusetts spent 70 minutes on the ground and wrought havoc across 38 miles, killing three people and injuring 200. The deadliest of the state's 181 storms was an EF4 twister that slammed the Worcester area in June 1953 — it killed 90 people, injured more than 1,000 and caused $250 million in damage.

New York has experienced more than 470 tornadoes ranging from EF0 to EF4, with most occurring south and west of the Adirondack Mountains. The Empire State's most costly year of storms was 1989, when 18 twisters led to 11 deaths and $175 million in damage.

One person has died because of New Hampshire's 105 tornadoes in the past seven decades. Vermont's eastern neighbor has seen a pair of EF3 events and had three years — 1981, 1986 and 2008 — with damage exceeding $2 million.

Tornado watch vs. tornado warning

The less dire of the two distinctions, a tornado watch is issued by meteorologists from the NOAA Storm Prediction Center when conditions in an area appear favorable for tornadoes or severe weather, according to the National Severe Storms Laboratory.

Tornado warnings come from local outposts of the National Weather Service when radar or spotters report a tornado and there is a serious threat to life and property in its path. Individuals should seek safe shelter immediately if they are in an area under a warning.

According to Ready.gov, the Department of Homeland Security's storm preparedness website, anyone under a tornado warning should do the following:

• Get into a sturdy building and find a safe room, basement or storm cellar. 
• If the building doesn't have a basement, get to a small interior room on the lowest level.
• Avoid windows, doors and exterior walls.
• Do not get under an overpass or bridge — a low, flat location is safer.
• Be alert for flying debris.
• Protect your head and neck with your arms if necessary.

Contact Austin Danforth at 651-4851 or edanforth@freepressmedia.com. Follow him on Twitter at @eadanforth.

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