Elie, Manitoba F-5 June, 2007

[Brandon Brown]

im afraid to start this thread under the assumption that many people have seen this video already, but this is a new one to me. this is probably some of the best tornado footage i have ever seen! note the new circulation forming to the left of the tornado and dropping a small funnel at the beginning. beautiful storm, its too bad it went into Elie and did the damage it did.

http://www.youtube.com/watch?v=3ScKKYV8u6E

 

[Bill Hark]

That is a longer version of the Elie tornado video that I searched for months for Storms of 2007. I found similar video from a different vantage point but I think the video link you posted is some of the best.

Bill Hark

 

[Mark Sudduth]

I cannot beleive this tornado went back and forth like that over some of the same area. That is incredible video. How often do tornadoes swing back and forth like a pendulum over the same general area? It looked like it was taking off from right to left across the frame and then it went back to the right and then came left again- all in the vicinity of that grain elevator. I assume that we are seeing vehicles and homes/buildings being pulverized towards the end there as well...amazing but utterly frightening.

 

[Chad Cowan]

I assume that we are seeing vehicles and homes/buildings being pulverized towards the end there as well...amazing but utterly frightening.

I believe this is the video that prompted Environment Canada to upgrade the tornado to F-5 after seeing a large building and van being thrown in the air at the 6:26 and 6:36 marks. If this storm had any forward motion, the tornado probably wouldn't have done more than F-3 damage, but sitting over the same place for an extended period of time allowed for the same areas to be pummeled over and over.

 

[Dann Cianca]

"It's not the mill, it's the town" ... kind of makes your heart sink.

That is incredible video, though I could hardly understand a word of the 'commentary' ... Mennonite or Hutterite Colony?

 

[Gerard Jebaily]

I wonder if the reason it was an F-5 was because it hit the same structures twice (from what I could see). Incredible footage of an incredible tornado!

 

[Ross Kimes]

Yeah I have heard of people talk about how that tornado may not have quite be an F-5. I don't know if it was on the same scale as the May 3rd or Greensburg, but it still looked to be a very impressive tornado.

 

[Tony Lyza]

I wonder if the reason it was an F-5 was because it hit the same structures twice (from what I could see). Incredible footage of an incredible tornado!

I think the F5 rating is based off the video of the a well-anchored home being lofted in one piece into the air and centrifuged out of the tornado. And I have a lot of doubt that the forward motion played a major role in that feat.

 

[Willie Dines]

I feel that the F5 rating was correct for the Elie tornado.

At the beginning of the video when the 1st close up of the funnel's contact point with the ground was shown, the core of the funnel was briefly exposed, showing that the tornado had a double wall structure, where the tornado has a thin concentrated core and then an outer core with a space between the 2 cores, but I also noticed that there were brief suction vortices that seemed to be embedded within the funnel also, thisa seemed to be evident a few times throughout the video.

The house being lifted near the end of the clip is probably the best example of what a tornado's brute force can really do, and what makes it more impressive is that it looked to be a brick home that was lifted.

Since I began studying tornadoes as a kid, I had been aware that tornadoes don't necessarily travel in a straight line, as they can become somewhat stationary and/or back track, but this one looked more like it was going round in circles in that particular area, which is the first I have seen that in a live tornadic event, but I have seen it happen in some of the experiments that I used to run with the tornado machine.

Thank you for posting the link Brandon, I think that it's worth while for other chasers and wind engineers to take a look at the video to give their thoughts on the video as well.

Willie

Note - The tornado machine I had, was not confined to being in a closed enviroment, like a box or cylinder, instead it was done via a small fan suspended over a sheet of peg-board, on top of a large bucket, with a hole cut into the side of the pucket to one side, allowing for the use of a smoke machine for the tracer.

 

[Scott Lincoln]

Yeah I have heard of people talk about how that tornado may not have quite be an F-5. I don't know if it was on the same scale as the May 3rd or Greensburg, but it still looked to be a very impressive tornado.

Since the Enhanced Fujita scale is a damage scale, wouldn't the forward motion not have alot to do with its EF rating? If it caused damage in the end that was EF5, wouldn't it not still be an EF5? (or F5 if thats what they still use in Canada).

I think I read a similar argument to this when people were comparing the Jarell, TX tornado to tornadoes like Greensburg and Moore. If we had a tornado intensity scale, I think it would be different, but weaker, slower tornadoes can cause as much damage as stronger, faster tornadoes.

 

[Willie Dines]

This is true, Pampa, Tx in '95 is another good example of that

Willie

 

[Chad Cowan]

I think the F5 rating is based off the video of the a well-anchored home being lofted in one piece into the air and centrifuged out of the tornado. And I have a lot of doubt that the forward motion played a major role in that feat.

The fact that the home was lifted in one piece tells me that it was not well-anchored. I'm not a structural engineer, but it seems to me that the (lack of) forward motion of the storm caused the structural integrity to be compromised by the tornado before the direct hit.

 

[Justin Turcotte]

Since the Enhanced Fujita scale is a damage scale, wouldn't the forward motion not have alot to do with its EF rating? .

I believe the Canucks are still using the F-scale. The original F-scale is actually an intensity scale. Fujita simply conected the Beaufort wind scale to the Mach scale. Turns out Mach 1 is an F12 tornado. It would appear Fujita designed his scale with intensity in mind but he needed the damage markers to ascertain the intensity since tornadic wind winds are rarely measured directly. Years of study have shown Fujita's wind speeds were too high and it seems over the last decade tornado damage surveyors have been trying to reconcile this by lowballing some of the more severe damage. In theory, EF should eliminate that concern. The EF scale is still more or less an intensity scale with a more sophisticated set of damage markers. I would argue the EF scale was adapted specifically to account for more accurate tornado intensity otherwise there would be little purpose for changing the original F-scale. The Elie tornado certainly fits the F5 mold but I'm not so sure about EF5.

 

[Greg Stumpf]

The Elie tornado certainly fits the F5 mold but I'm not so sure about EF5.

For the FR12 Damage Indicator (DI), otherwise known as a single- or double-family residence:

F = EF

Therefore, if an FR12 DI was used to rate the Elie tornado, as it was for the most part, then it is both an F5 and an EF5. The only difference is in which wind speeds you believe are associated with that specific Degree Of Damage (DOD).

What really needs to be recorded are the specific DI DODs, and then as the wind estimates get better, they can easily be translated from the recorded DOD information.

 

[Patrick Boomer]

The fact that the home was lifted in one piece tells me that it was not well-anchored. I'm not a structural engineer, but it seems to me that the (lack of) forward motion of the storm caused the structural integrity to be compromised by the tornado before the direct hit.

Dave Carlsen, lead investigator for Environment Canada on the Elie tornado, gave a few interesting facts regarding the F5 rating in this thread over at the Canadian Weather forums:

"Well-built and -anchored homes were gone. Not moved, gone. At first, I thought they were just moved, that the debris belonging to the destroyed houses was the stuff laying next to the foundations.

Then we got the video. You can see one of the houses (huge j-bolted down, well built, 1970s vintage) not being blown off its foundation but actually being ripped out of the foundation, only to explode in midair. There's (1) for F5 determination.

Also, later in the video, you can see a van. It gets picked up, about 100 feet into the air, and is thrown around. We determined where it came from and found it laying in a field during the damage investigation. Turns out that the van was a 3/4 ton van, full of drywall. Tossed over a mile. There's (2) for F5 determination."

That is some amazing video.