Tornado lift?

August 7, 2006 3:54 AM

Tornado lift?

After watching some tornado vids on You Tube I started wondering about this. How many pounds of dirt/debris can the average tornado suspend at its peak?

posted by jeffr062 to science & nature (5 comments total)

Well, this is a complete wag and is definitely not the most accurate way to go about it, but the formula for wind pressure is:
P = 0.00256V^2
where V = wind speed (mph) and P = wind pressure (psf)

We'll assume that the HORIZONTAL component of wind is fierce, rips and tears things up, and blows them around; and the VERTICAL component of wind speed of a tornado is weaker (judging by all the footage I've seen) and is does the lifting. I'm going to assume that while the horizontal tangential motion is 100-200 mph, the vertical motion is maybe 100 mph (25.6 psf) on average. And an average tornado is maybe 50 ft in radius. So pi(50^2) = 8000 sq ft, multiplied by 25.6 psf is about 200,000 lbs (100 tons).

Again, just a wild guess. Obviously this goes up exponentially with tornado size, and who even knows how strong the updraft velocity (or mean velocity) within a tornado is. I don't think that's been quantified anywhere.
posted by hodyoaten at 7:46 AM on August 7, 2006

Thanks hodyoaten, nobody else would even venture a WAG.
posted by jeffr062 at 2:15 PM on August 7, 2006

Great WAG.
posted by dragonsi55 at 5:44 AM on August 8, 2006

I don't think that's been quantified anywhere.

Well, not for lack of trying.
posted by baylink at 6:24 PM on August 8, 2006

more
posted by baylink at 6:26 PM on August 8, 2006