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| Funnel cloud over Middlebury, Vermont as viewed from the Marble Works. An EF-1 tornado is confirmed to have touched down yesterday to the northeast of downtown. |
DETAILS:
The tornado was only 75 yards wide and traveled just a mile and was probably on the ground for not much longer than five minutes.
In the grand scheme of American tornadoes, this one was weak. Top winds, though, reached 110 mph and hit with destructive force.
The tornado threw a barrel through the window of one house before doing its worse damage to a single family home on Painter Road.
The garage was pulled off the house and thrown a few dozen feet down the driveway and destroyed. A car was overturned and debris from the structure was thrown hundreds of yards.
Before the tornado dissipated, it snapped off a bunch of pine trees at mid-trunk. This was clearly a dangerous storm.
Interestingly, after the big outbreak of tornadoes in the South Thursday, the Middlebury storm was the only tornado reported anywhere in the United States on Friday.
VERMONT TORNADO COMPARISONS
As most of us Vermonters know, tornadoes are rare in Vermont. We average roughly one every year. They're super rare this early in the season. Tornadoes and their parent thunderstorms almost always need warm, humid air as one ingredient to sustain themselves. We actually had that yesterday, which again, is unusual in March.
There was only one other March tornado recorded in Vermont. It hit Bennington County on March 22, 1955. That record is suspect as weather data from that day in Vermont and adjacent eastern New York show that rain and snow fell that day and temperatures stayed in the mid and upper 30s. That does not sound conducive toward tornadoes. I'm not buying it.
Friday's Middlebury tornado, was obvious.
By Vermont standards, Friday's storm in Middlebury was actually a fairly strong tornado. Most of the recorded twisters in the Green Mountain State were actually weaker than yesterday's storm.
Tornadoes are rated on a zero to five scale called the Enhanced Fujita scale or EF. This was a high end EF-1, with top winds estimated at 110 mph. EF-1 tornadoes have winds of 86 to 110 mph and EF-2 twisters are 111-135 mph, so you can see we were close to EF-2 with this one.
I could only find a record of one EF-3 tornado in Vermont h and no known EF-4s or EF-5s. Even that EF-3 is suspect. It was that strong when it was in New York on May 31, 1998, but I believe it had weakened to an EF-1 by the time it reached Bennington County.
Two people were injured in the Middlebury tornado, but fortunately the injuries were relatively minor and not life-threatening. Injures are exceedingly rare in Vermont tornadoes, because Green Mountain twisters tend to be so weak.
In tornado databases, I could only find 10 injuries from tornadoes in Vermont since 1950 prior to Friday. (Of those, seven were injured in a single tornado in St. Albans in August, 1970).
There are no known deaths for tornadoes in Vermont. I'm certainly happy that zero Vermont tornado death toll stands after Friday!
FORECAST AND RADAR
One takeaway from this tornado is how good some of the computer models are at picking up on tornado threats. On Wednesday, as WPTZ meteorologist Ben Frechette noted on Twitter, a tornado parameters model focused on the possibility of this happening in western Vermont, with a bullseye on Addison County, where Middlebury is.
The day before the storm, NOAA's Storm Prediction Center began advertising a very low, but not zero chance of tornadoes in and around Vermont.
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| Two days before the Middlebury tornado, computer models picked up on the possibility of a twister in western Vermont, with a bullseye on Addison County. This forecast proved amazingly accurate. |
As the line of thunderstorms advanced across New York toward Vermont, you could see brief moments of rotation on radar images, but the threat from the storms was mostly from straight line winds.
I'm not at all surprised - nor am I at all dismayed - that the National Weather Service in South Burlington did not issue a tornado warning in advance of the Middlebury twister.
In this kind of set up, with quick spin ups on a squall line, the signs of a tornado on radar are fleeting - you get a quick hint of rotation, then it disappears. In just a moment, a tornado threat appears and disappears. There's no chance to issue a tornado warning.
However, NWS South Burlington knew the thunderstorms were strong and potentially dangerous. Middlebury, and much of the Champlain Valley for that matter, was under a severe thunderstorm warning at the time.
In retrospect - and this became apparent only after the brief tornado had touched down and then lifted - radar had what is known as a tornado debris signature, which is a fancy way of saying radar detected stuff that had been blown into the air by the tornado.
Other severe and damaging thunderstorms hit parts of the Champlain Valley and central Vermont Friday, toppling numerous trees and power lines. There were signs of rotation in the storms near Montpelier, but there's no concrete evidence - at least not yet - of any tornadoes elsewhere in Vermont.
Of course, I imagine some tornadoes go undetected in Vermont. A weak, rain wrapped tornado that hits some forest with nobody nearby would almost surely go unnoticed.
There's no trend line that indicates tornadoes are getting any more common or rare in Vermont. However, there has been an increase in the number of times Vermont is under conditions favorable for the formation of tornadoes.
This is part of a national trend. In the United States, there has been a tendency for tornado activity to move east over the years. They are more common in the eastern United States than they used to be. That's especially true in the Southeast, where Thursday's tornado outbreak caused so much destruction. And where new tornadoes are possible today and tomorrow.
Meanwhile, tornadoes are relatively less common in "tornado alley" - the Great Plains. Scientists are studying why this eastward shift is occurring, but climate change probably has a hand in it.
With climate change, drier air is able to punch further east across the Plains. Meanwhile, even more warm and humid air flows northward off the Gulf of Mexico than previously. The clash of dry and warm air is one ingredient for tornadoes, and this pattern shift can also concentrate tornadoes further east than they once did.
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