A glance at the topographical map of missouri and a map of historical tornado activity indicates that the Ozarks provide a substantial degree of protection from tornados to a portion of the state of Missouri

It shouldn't be impossible to mimic this ozark effect by creating large walls on the west and south sides of a city with a dense population. A 300-meter high wall should provide noticeable protection.

If the project is done in pure concrete with a base as wide as it is high, a 1km section of wall will cost 4.5 billion, but hopefully, it shall be possible to use cheaper fill materials to bring the cost down.

At this point however, I must admit the cost of such a wall is worth more than the property it could concievably protect-- for now.
-- Madai, May 21 2013

The Ozarks may be offering a "rain shadow" effect. The prevailing winds come up from the south or southwest, humid because of originating over the Gulf of Mexico, so it would rain more on that side of the Ozarks, and northerly of them there would be less humidity in the air. Not as much-less as the rain shadow of the Rockies, because the Ozarks aren't as high.

The Ozarks are also modest in extent, so humid air can go around them. But near to them, where the rain shadow happens, that would be the place somewhat shielded from tornadoes.

In the plains to the north of the Ozarks, it is the condensation of humidity into rain, when a warm-humid weather front meets a cold front, that provides the energy that drives tornado storms.
-- Vernon, May 21 2013


Such a wall with a gently sloping outer face built circumferentially around a city would make incoming tornadoes catch air and jump cleanly over the city.
-- bungston, May 21 2013


Talk about an urban growth boundary...
-- scad mientist, May 21 2013


Fascinating tornado facts:
~A tornadoes' direction of spin is influenced by which hemisphere it is in. Northern tornadoes usually spin ccounter-clockwise.
~North American natives told settlers that tornadoes never strike at the joining of two rivers.
~Lots of cities have been hit by a tornado but never a downtown core with large buildings.
~I've watched one form overhead and touch down about a kilometer away... It was awesome!

hmmm
I wonder if anyone has figured out how to use HAARP to make directed tornadoes and hurricanes yet? If not yet, they will.
-- 2 fries shy of a happy meal, May 21 2013


A wall that large could certainly house a tornado, if it wasn't filled. Instead of a wall make it a trap and lure tornadoes inside using a trail of old trailers. Once it is inside, shut the door.
-- rcarty, May 21 2013


^(+)
-- FlyingToaster, May 21 2013


Ha - a wall to prevent tornadoes... How about abandoning the stupid SUVs and other gas guzzlers that have caused global warming, which is the reason why these monster storms will only continue to increase in ferocity? Try building a wall around New York City to stop it from being inundated by the sea. Good luck with that.
-- xenzag, May 21 2013


" If the project is done in pure concrete with a base as wide as it is high, a 1km section of wall will cost 4.5 billion, but hopefully, it shall be possible to use cheaper fill materials to bring the cost down."

It sounds like an arcology project. While pure concrete (99.999 fine?) is pricey, there are plenty of crushed trailers and automobiles to use as fill.

You could also honeycomb the structure and sell living and commercial space in the cells.
-- normzone, May 21 2013


//How about abandoning the stupid SUVs and other gas guzzlers that have caused global warming//

Good point. There have only been tornadoes in the last few decades.
-- MaxwellBuchanan, May 21 2013


//How about abandoning the stupid SUVs and other gas guzzlers that have caused global warming, which is the reason why these monster storms will only continue to increase in ferocity//

That is utter and complete nonsense on every level. About the only thing that actually is happening is population growth, particularly in the West and South and of course at the shores, which is putting more people in harm's way. But just a wee bit of googling will show you that we've had multiple periods of waxing and waning tornado activities, ditto of course for hurricanes and the like.

And only a complete and utter lack of thought clarity-- truly -- would blame SUVs -- a mode of transportation that has existed in any meaningful numbers for less than 30 years -- for climate change.

Google itself, and the rest of the Internet is a likelier culprit then -- just do the math on data center power consumption since the 80s.

We're not running out of oil, of food, of water, or of climate, and the rest of the planet owes us pretty much everything in advance for that asteroid we're going to steer out of the way some day. So turn on the polluting AC if needed, and chill.
-- theircompetitor, May 21 2013


A cursory Google suggests that the supercell formations responsible for tornados are formed when the moist gulf air hits dry prairie air. Now, if the differences can, to some extent, be ablated, then you should be able to mitigate the problem.

So, flood as much of the midwest as possible. Admittedly, there's not much rainfall, and it's a bit high to expect much inflow. But a few lakes and canals here and there, preferably surrounded by Forrest should buffer the situation a bit.

The extra biodiversity will do no harm either.
-- bs0u0155, May 22 2013


// the rest of the planet owes us pretty much everything in advance for that asteroid we're going to steer out of the way//

Not if several billion Chinese and Russian astronaut miners have chipped it away first.
-- MaxwellBuchanan, May 22 2013


//Tokyo bay where nature was thwarted by making an artificial island, Odaiba

Just don't mention Osaka airport, or whatever the old Yokohama dreamland project was, built on old landfill site. They don't always get it spot on.
-- not_morrison_rm, May 22 2013


[MB], I meant us humans, not us Americans.
-- theircompetitor, May 22 2013


There's an upward trend in tornado sightings since 1950, so I suppose it's fair to suspect global warming does have a role.

However, there are regions of the US where even the 1950's rate of tornado formation is not a good thing.

That said, if you generalize "abandon gas guzzlers" to "use energy more efficiently" it's hard to object.

It is my hope we can enhance human quality of life as we reduce energy use-- safer cities that require less maintenence/repair, shorter commutes(thus less gas needed for daily life), lower HVAC bills etc.
-- Madai, May 23 2013


The key word there is "sightings". More people, more radar. More reports.
-- bs0u0155, May 23 2013


yes, in the 50s, those cell phone videos of tornadoes were few and far between.

For energy to be "used more efficiently", you really need only one thing -- price it according to market conditions. The money savings are sufficient inventive in it of themselves
-- theircompetitor, May 23 2013


Instead of a wall, install apartment buildings that are miles long with very small windows facing the tornado winds. That way the towns you are trying to protect could double in size.

"Hello! Where is apartment # 30,667?"
-- popbottle, May 27 2013


First, a month after the tornado wall was built, you'll discover that all wildlife breaks down, because the animals cant get to their water sources. When rats and snakes start entering the towns in large numbers, and there are major fish- death events reported in the contaminated lakes and rivers, it will begin reaching the headlines, and people will start wondering if it has anything to do with the large walls.

Then you'll discover that the wall stops all winds and breezes and causes warming to unprecedented temperatures, which in turn bring a dry-out of trees, followed by creating snow conditions for extra cold winters, and finally evaporating the fossil water through cracks in the ground caused by all this wear and tear allow the lava to break through and voila - you have a volcanic eruption.

But the tornado won't pass.

By the way, in my country they tried such a wall. Against terrorism. Many, mistakenly, still think it was a good idea.
-- pashute, May 29 2013


//There's an upward trend in tornado sightings since 1950, so I suppose it's fair to suspect global warming does have a role. //

Would the sightings have gone up by about two-and- a-half fold? Only I'm thinking that sightings of just about everything should have gone up by about two- and-a-half fold, there being about two-and-a-half times more people around now than in 1950.
-- MaxwellBuchanan, May 29 2013



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