Probably time for city hall to make basements in new contruction... (Houston: home, construction)

[mSooner]

The good news is that they're extremely rare, probably somewhere between five and ten percent of all tornadoes.

Actually, I believe it is 1-2%

Locomusic01--stick around. Someone presenting actual facts and logic about tornadoes & severe weather--YES!

As for driving away, yes, some people were saved in Moore by doing so. But that doesn't automatically make it a good idea.

Totally agree. While we are hearing all sorts of hoopla about how little warning Moore had, the truth is they had quite a bit compared to most tornadic events. OKC is blessed with Gary England and his severe weather team, as well as all the other weather enthusiasts, researchers, and chasers on the ground. I was streaming News9 coverage on my iPhone during the tornado and people had a very good idea of what was going on and where the tornado was, down to tiny intersections. Most of the time, you aren't going to get that detail and time.

[locomusic01]

Thanks Sooner!

Officially it's only a couple percent, but I think it's quite likely many violent tornadoes occur without being recorded as such since they need to strike a well-built home or other damage indicator that was capable of registering EF4-5 damage. Just as an example, the tornado that occurred in Rozel, KS on 5/18 only struck one home and caused EF2 damage, but it was observed by a mobile NOXP radar as having wind speeds near 190mph, so it was rated EF4 based on that. If it weren't for the mobile radar (and only a few tornadoes a year are monitored), it would have gone in the books as an EF2.

In any event, you're right about the coverage. Oklahoma, and especially the OKC Metro area, has the luxury of having probably the best tornado coverage in the world. The only other place that comes to mind is the Birmingham Metro with James Spann, JP Dice, etc.. and their network of skycams. Even in Moore where there were chasers giving street-by-street coverage, a slow-moving tornado and pretty good lead time, we can't pretend that evacuating was the best decision for everyone. Some people did do it successfully, sure. But others tried to evacuate and couldn't, and they were forced to abandon their vehicles on I-35 and scramble to take shelter somewhere. Call me crazy, but that's not a situation I find desirable. All it takes is a couple of stopped cars to cause a huge traffic jam, and then you're a sitting duck.

I'll repeat it again. If you're in a car and you're struck by a violent tornado, you're almost certainly going to die. If you're in your safe place at home and you're struck by a violent tornado, there's still a pretty good chance you'll survive. It isn't guaranteed, but it's infinitely better odds than being stuck in a car.

[locomusic01]

So, after last night does everyone still think evacuating by car, especially in or near an urban area, is a good idea? Folks in the OKC Metro were extremely lucky that there weren't dozens, if not hundreds of fatalities. The supercell that produced the monster tornado near El Reno/Union City cycled before reaching OKC, and the cells that had formed behind it began putting out a bunch of outflow that never really allowed the original cell to produce another strong/violent tornado. That's really the only thing that saved OKC from having a mass-casualty situation. Every freeway in the area was completely packed like parking lots. Thousands of cars stuck on the freeway like sitting ducks in the path of a supercell that had just produced a massive, violent tornado.

Anybody wanna be one of these cars? I sure don't.

[TheOverdog]

I've always thought that basements should be mandated in TX to move our cooling equipment into the heated/cooled envelope of the house, as putting all the ducting in a hot attic is a pretty bad idea.

As for tornadoes, I don't think mandating a basement in every home is necessary for that or even a good idea, but in all public buildings I think it would be a good idea or at least a hardened room, and that public buildings should spread to be within about a 10 minute walk/half mile for everyone in the city. Or if it's a master planned community, then a storm shelter should be included in the community-public buildings. Between schools, fire departments, libraries, rec centers, and official buildings I think many metroplex cities would come pretty close to this standard without having to build many whole new buildings.

[EDS_]

Originally Posted by TheOverdog

I've always thought that basements should be mandated in TX to move our cooling equipment into the heated/cooled envelope of the house, as putting all the ducting in a hot attic is a pretty bad idea.

How's that supposed to work with pervasive gas heat and the fact that residential basements are very difficult and expensive to build and maintain around here. Possible sure reasonable not so much IMO.

[Texas is only OK]

I must be totally wrong about this since no one has said it....I had heard years ago that the reason this part of the country doesn't have basements is some kind of building/construction issues due to the flood plain and the soil shift....? Anyone know?

[mSooner]

The reasons that have been discussed and immediately come to mind:

No need to dig very far as they need to up north to get below the frost line. Hence what is a necessary part of construction in the North is an necessary extra expense here.

Our soil sucks and it would be pricey to build something sound enough to avoid it heaving all over the place.

I've also heard our water table is higher, but I cant speak to that myself.

[TX75007]

Good article on the lives saved by evacuating in Moore during the first storms on NPR. And then the tradeoffs in the latter storm due to the flooding.

No 'Universal' Best Practice To Save Yourself From Tornadoes : NPR

Above ground shelters all survived the F5. But notice that some were damaged and had debris forced inside.

Oklahoma tornadoes: Aboveground shelters stood up in face of EF5 Moore tornado | News OK

A good above ground shelter runs $4-6K. I imagine a shelter built at the time the pad was poured would be less.

Again, an F5/F4 might rip the door off and fill the shelter with debris.

[PanTerra]

Originally Posted by Texas is only OK

I must be totally wrong about this since no one has said it....I had heard years ago that the reason this part of the country doesn't have basements is some kind of building/construction issues due to the flood plain and the soil shift....? Anyone know?

Here is the Geologic Map of Dallas.



Do you see that green swath with the "Kau" label, running smack dab through the middle of the county? That's the Austin Chalk, the White Rock that is ubiquitous in the names of so many things around here. It is the ancient continental shelf so it can get pretty thick. That's the problem. It is the surface formation right below the thin veneer of soil. It is also why we can have very tall buildings - it's hard and stable. If you get off of that, it won't be as costly as you are built on shales and marls - soft and possesses a high porosity so can hold lots of water, but then you will have to worry about dewatering.

[gymrat]

We have the white rock under our house. There is only about 4-6" till you start digging up huge chunks of rock. When we added my husbands garage a few years ago the foundation is an art in engineering. As they were digging for the foundation it kept filling up with water. They would pump it out and it would be back full again the next day. There is a spring somewhere nearby and the water runs along the top shelf of the rock and down to the creek. Since it does not "pond" on our lot there is no problem for the foundations, whew! When the pool was put in years ago it was a lot of $ to get them to dig because of the white rock. With a combo of the white rock and the water, if we had a basement it would be flooded. I'd have that cistern I was wanting, hahaha.
No way in HADES would I dig a basement under my house for it to flood. And you sure as heck would not find me putting my family down there in a storm with the risk of flooding AND being trapped and unable to get out.


As for those underground shelters featured on WFAA, the company does mention that their underground shelters come with a hydraulic lift to open the door in case it is covered with debris.
I want to make a large closet we have into a safe room. Just for tornados and emergencies, in case. Now, for any nuclear attack, nope! I sure don't want to be the only one left