# Could we stop a tornado this way?

## Main Question or Discussion Point

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mfb
Mentor
Take an F2 tornado, at 50m/s, with a typical size of 100m and maybe 1 km high. Its air has a kinetic energy of the order of 100 GJ. The J58 engine can deliver ~150 kN, at 50 m/s this is a power of 7.5 MW. It needs 4 hours of running before its overall energy output matches the energy in a single F2 tornado, and if we consider momentum instead of energy the comparison gets even worse. In addition, the tornado won't sit around and wait. Increasing the number of engines doesn't help much - the jet engines will have a negligible impact on a tornado, no matter what you do.

Trying to prevent a tornado makes the numbers worse by orders of magnitude because you have to cover a huge area.

Evo
Thank you. A four hour running time could be handled, as these engines could sit at idle, whenever a tornado watch is issued (or whenever conditions are favorable.) These engines, if not able to be used to destroy a tornado, could at least manoeuvre a tornado's path out of the way of a town.

mfb
Mentor
You cannot deploy a turbine on every square kilometer of land. And you cannot predict tornados precisely hours in advance, so you do not have 4 hours.
These engines, if not able to be used to destroy a tornado, could at least manoeuvre a tornado's path out of the way of a town.
Would still need much more power than available.

Evo
You would not need to deploy an Engine on every square kilometer. Also, you are able to predict tornado's well enough to be able to tell if a major storm front will form later in the day. Also, I have a question. Would a Rocket Engine or Rocket booster produce enough power?

mfb
Mentor
They would come closer, but there is no way to have such a rocket mobile and ready to fire. Also, the effect would still be small - it is by no means guaranteed that a rocket engine is sufficient to stop it.

Also, rocket engines cost much more than rebuilding a few houses.

Evo
If there is no way to have a rocket mobile and ready to fire, then how are Rockets able to launch on the T - Minus count and launch at the push of a button? Now yes, If I did receive money, I would test this on a much smaller scale, But this is still practical. This program would not protect a few houses. This program would protect entire cities and neighborhoods where infamous tornado's, have already hit. The ten costliest tornado's in United States History, added together, equals $16,825,720,100 dollars. That is 16 billion dollars. It takes 150 Million dollars, to launch the average space craft, INCLUDING all of the parts and mechanics that wouldn't be used in the Tornado protection program, so the costs make since. Who knows how much damage all of the tornado's that have ever existed have produced. This program is meant to protect neighborhoods and entire cities from the violent super tornado's that are well known of. A tornado, can hit anywhere in the united states, regardless of it's physical stature such as mountains etc. Now, some of the area's will produce more violent tornado's than others, and that's true. But many majors cities, such as Washington D.C, Oklahoma City, Minneapolis, Minnesota, Green Bay, Wisconsin, Chicago Illinois, Omaha Nebraska, and many more, lie in the wake of tornado alley. This program would receive funding from the major cities I've listed. Why? Because if this program is proven to work, it would be a major insurance write off for the cities. Insurance companies would no longer have to pay out so much money to storm damaged cities, saving the cities, and individual civilians, Millions of billions of dollars in damage, saving more money than is spent. SteamKing Staff Emeritus Science Advisor Homework Helper If there is no way to have a rocket mobile and ready to fire, then how are Rockets able to launch on the T - Minus count and launch at the push of a button? You are overlooking all the planning and work which must be done to get the rocket ready to fire at the push of a button. It's not something done on a whim or at a moment's notice. Tornadoes are extremely short-lived storms. The longest distance a tornado touched down in the US was 219 miles, and was estimated to move at more than 70 mph while on the ground. This storm probably had a whole series of funnel clouds touching down in succession as the storm front moved. The average distance a tornado touches down is about 5 miles, and the width of the path is about 500 feet. The shortest path of destruction was seven feet long. https://en.wikipedia.org/wiki/Tornado You'd probably have much better luck convincing cities to build walls 1000 meters high to keep tornadoes out. Evo I do not know. Building walls 1000 meters high up would be an eye sore for people, also being extremely costly to construct, engineer, and build. Yes, it would take a long time to prepare a jet engine, but the main question im asking, is: Would it work? Thank you for replying. jim mcnamara Mentor I'm going through this exercise because you put effort into your question. I do not believe you understand enough to get a real understanding of all of what might be involved. So, by just using one parameter, Horsepower, here is what I see. The answer is no. Aside from the logistics of moving and stabilizing the the engines when in position, which is monumental [see last paragraph], let's look at your basic premise - jet engine thrust has enough "oomph" to have a major effect. Let's see: per this page http://www.dartmouth.edu/~ears5/handouts/TornadoEnergy.html, an F3 tornado 1km wide and 1km high has output of 300000000000 Joules per sec, converting to HP we get 402,144,772 HP. That is 400 million horsepower. This page from Hill AFB, http://www.hill.af.mil/library/factsheets/factsheet.asp?id=5786 lists the axial output of the shaft of the engine J58 at 160000HP. So to 'negate(if that were even possible)' for an F3 tornado we need a decent fraction of 400 million HP. At this point we leave Science entirely. So let's pretend we need 100 million HP or about 625 jet engines. Or 625 trucks as you proposed. And the engines have be mounted vertically on really tall racks, that will resist both tornadic winds and the jet thrust, all the while the entire ensemble has to be able to move at decent ground speeds over all kinds of terrain just to confront the tornado... I'm not going to do any more. But I do know if you persist in claiming your idea will work, the mentors here will probably lock the thread. PS: did you see the number of tornadoes that were created in the Midwest just this last week? It would cost about 10% of the$US GDP to field enough trucks to handle them. And feasibility counts for everything you do in Engineering. Everything.

Evo
Mentor
It's time to close this down. Fearguy, I suggest that you study tornadoes. I live in tornado country, many times the tv meteorologists are watching tornado activity in one area, when suddenly a tornado comes out of the blue 75 miles away and actually touches down. Sometimes there are multiple tornadoes miles apart. Which will hit open pasture and which will hit a crowded subdivision, no one knows until it happens.

Even when a tornado has been spotted and the sirens go off, you don't know if it's coming at you, or even if a tornado will go all the way to the ground. Last time there where 3 tornadoes at once, I had dropped my daughter off at a friend's just when the sirens went off, it wasn't raining, and the sky just had a few light clouds. I had a 30 minute drive home, with sirens blasting, luckily all three tornadoes were to the west of me where I could see them and they kept to a northerly course while I was heading south. You just do not know with tornadoes. They could have changed course at any time.

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