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A monstrous tornado that may be remembered as among the largest and most destructive in American history roared through a heavily populated suburb of Oklahoma City, cutting a swathe as much as two miles wide and flattening homes, shops, hospitals and, perhaps most devastatingly, schools that had no time to evacuate.

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Tornado history:

Extreme event spot on the centre of probability map!

Remarkable pictures:
http://www.dailymail.co.uk/news/article ... uburb.html

The thing to bear in mind as well is that many American homes are little more than matchstick boxes covered in sheet rock. Not that anything stronger would have likely withstood this tornado.

The place is called 'Tornado Alley' - hmm I wonder why that is. Bit like people living in, say, 'Floodplain Avenue' then being surprised when the water is up to their armpits.
If that school that was flattened had no storm shelter then shame on the adults that let that 'oversight' happen. They have storms there for crying out loud.

Yes protection against even 200MPH winds is possible in a SUBSTANTIAL structure of reinforced concrete without any windows* and with access via a right angled passagway with heavy doors.
A soundly constructed basement is best, but suitable above ground structures can be built.
Tornadoes though very dangerous do pass very quickly compared to most other problems. Shelters can therefore be very basic with no, or very minimal provision for heating, lighting, cooling, sanitation etc.
The risk is normally over in minutes.

*some authorities recomend very small windows, no more than 100mm across and glazed with polycarbonate at least an inch thick, so as to permit of observing exterior conditions.

I heard on the news that they have had a serious tornado here in the 90s. Lightning striking twice?

While this event on its own isn't a proof of global warming, it is one of a series of extraordinary weather event to have struck the USA recently. You would think that they might start putting 2 and 2 together and not getting 5 for a change!!

But then there's just too much money to be made out of a disaster like this: all that rebuilding; better building codes that cost more money. It's a BONANZA!! What's not to like!!

kenneal - lagger wrote:It's a BONANZA!! What's not to like!!

24 deaths?

See: http://www.guardian.co.uk/world/2013/ma ... ve-updates

I was being facetious.

And it's about 90 deaths as at lunch time today, according to Sky News.

kenneal - lagger wrote:I heard on the news that they have had a serious tornado here in the 90s. Lightning striking twice?

While this event on its own isn't a proof of global warming, it is one of a series of extraordinary weather event to have struck the USA recently. You would think that they might start putting 2 and 2 together and not getting 5 for a change!!

But then there's just too much money to be made out of a disaster like this: all that rebuilding; better building codes that cost more money. It's a BONANZA!! What's not to like!!

So long as their lifestyle isn't up for negotiation. That's what matters.

stevecook172001 wrote:The thing to bear in mind as well is that many American homes are little more than matchstick boxes covered in sheet rock. Not that anything stronger would have likely withstood this tornado.

Like the suburbs of London would look any different if subjected to the same 200 MPH winds. Brick faced houses do better then wood against flying debris but the windows still blow out and the roofs (even slate) fly off from the differential in air pressure , something like five psi outside to the 15 psi inside the building. Look at the building on the left that is moved more or less intact two thirds off its foundation. You call that poorly constructed?

Considering the destruction, the death toll seems to have been very low. Many houses had storm-proof basements or other refuges, I heard.

vtsnowedin wrote:

stevecook172001 wrote:The thing to bear in mind as well is that many American homes are little more than matchstick boxes covered in sheet rock. Not that anything stronger would have likely withstood this tornado.

Like the suburbs of London would look any different if subjected to the same 200 MPH winds. Brick faced houses do better then wood against flying debris but the windows still blow out and the roofs (even slate) fly off from the differential in air pressure , something like five psi outside to the 15 psi inside the building. Look at the building on the left that is moved more or less intact two thirds off its foundation. You call that poorly constructed?

Yep, fair points V.

The suburbs of London would probably suffer at least as badly as the buildings in this disaster.
That however is not the point, London does not (yet !) suffer from regular tornadoes but Oklahoma does suffer from tornados and should therefore be better prepared.
There will always be some people caught outside and too far from shelter, and such persons are regretably exposed to risk.

I do find it shocking though that a school seemed to have no suitable shelter from an entirely forseeable event.
For a new structure it should be possible to build a central corridoor that is resistant to extreme weather.
For existing buildings, an external but nearby shelter might be best, buried if ground conditions permit.