Many, Many Tornados Hit US South - 230+ Dead, Lots of Mess

[Broomstick]

Last night was a bad night for many in Alabama:


If I have the right tornado, this was over a mile in width (that's more than 1.6 km):


Of course, it wasn't just Alabama - at least six states had tornado outbreaks yesterday, and the storm system that spawned them is still in existance, headed towards the East Coast and places like Washington, DC and New York City.

The Wall Street Journal has a pretty good slide show. Note that in many of the photos branches and bark have been entirely stripped from the trees. That was done by debris suspended in the high winds of the vortex. Note also that brick and masonry buildings were destroyed as well as wooden ones.

Hundreds, if not thousands of homes destroyed, hospitals packed with the injured, streets blocked, power out... it's a mess. Injuries occurred from collapsing buildings, flying debris, and so on. The storm system that spawned all this is still in existence, headed towards the east coast and places like Washington, DC and New York City.

Here's the Tuscaloosa tornado caught in action. Tuscaloosa is a city of 83,000, and this tornado plowed through the central area of the city and the University of Alabama. Where it went the buildings are gone, down to the foundations. At 0:48 you can see a large piece of debris flying through the air next to the vortex. It's an upside down house.


The problem here is not lack of preparation - it's the intensity of a storm. A mile-wide tornado is not a small one. While the typical tornado has winds "only" about 177 kph the big ones can be up to 3 km wide and with winds up to 480 kph. There's some talk that this outbreak may surpass that of the Super Outbreak of 1974 once the dead and the damage have been added up. This April has set an all time record for tornadoes in the US, though thankfully not all have been the massive ones.

The only good thing about such storms is that they don't stick around long - I hope none of you have to ride one of these storms out, but if you do, it will likely be the most terrifying 10-30 seconds of your life. Remember, get away from the windows, and get under something so if the building you're in blows away or collapses you'll have some protection. They're loud, and your ears will pop. The "classic" tornado comes with a green sky and sounds like a freight train, but that's not always the case. (Personally, my theory is the roar of the wind is what sounds like a train engine, and the sound of debris hitting things and breaking up is what imitates the "clack-clack-clack" of the wheels on the rails, but it's not like at the time I was hunkered down hoping the damn thing missed me I was really concentrating on analyzing the situation. Especially as the first two times I was under the age of six.)

Yeah, I worry about this - I've spent most of my life in Tornado Alley. This week's outbreaks were mostly in the "Dixie Alley", known for "long track" tornadoes, those that plow through long lines of landscape. I'm up in "Hoosier Alley", where they usually aren't as violent as some areas, though back in 2008 in my area - and by "my area" I mean the next day I was picking debris like clothing and large pieces of roof and a car bumper out of my yard and off the top of my building - a "small" tornado around F1 leveled part of a building made of cinderblock, reinforced concrete, and steel at a local mall. We were huddled down in a pitch black house listening to pieces of building going by and wondering why the hell we couldn't hear the warning sirens, but we didn't actually get hit at my house. That was a small tornado. What swept through six states yesterday were BIG tornadoes, possibly at the top of the scale.

Oh, and the really charming thing - this isn't the peak of tornado season. We will definitely see more of these, though hopefully not worse that this week.

[Broomstick]

This link has more video from Tuscaloosa. The one at the top of the page was taken just minutes after the tornado passed, you can see the sky lightens throughout the video as time passes. The sound you hear from 0:16 to 0:36 that's rising and falling isn't a car horn, it's the warning siren, probably a system that rotates hence the rising and falling volume effect. If you hear that in the US Midwest and adjacent areas it means take cover.

The Tuscaloosa tornado has been tentatively rated as an EF4 (on a scale of EF0 to EF5, five being the worst) but that might change with further information as it is plain to seen affected areas are a bit chaotic today. Debris were flung up to at least 2200 meters according to weather and airport radar. Yes, you read that right - debris flung over two kilometers into the air. The National Weather Service is still investigating, but it looks like this one was on the ground for nearly 500 kilometers, plowing through Mississippi, Georgia, Alabama, and finally dissipated in the Carolinas. If confirmed this would bust the [url=tp://en.wikipedia.org/wiki/Tri-state_tornado]1924 Tri-State Tornado[/url] distance and be a new world/historical record.

In other words, what happened yesterday was extraordinary even for the part of the world that gets more tornadoes than anywhere else.

The death toll is now up to 283, and expected to continue to rise as more bodies are found in the rubble.

[Broomstick]

Well, although there are no comments the "view count" number has been going up so I'll assume there is some interest in this topic.

Aeriel footage of a tornado path:

[Sea Skimmer]

It’s not very hard to believe that 200mph wind can blow sheet metal ect… well over a mile into the sky. I’d think the twister could carry it as high as its own height. The death toll is probably going to go way over 300 judging by the blocks upon blocks of completely obliterated structures in some areas. Even light clad concrete buildings will fail under that kind of wind load.

[Broomstick]

All true.

There WAS a warning the day before. One of the things the National Weather Service does is, of course, try to predict bad weather. More than 24 hours in advance it was very clear that the weather systems (jet stream, Gulf moisture, etc.) were aligning for heavy storms and tornado risk. Even up where I am, north of where the main body of the storm was predicted to hit, the news channels (both radio and TV) were warning people of the risks of severe storms and telling people to have a plan where to go if a tornado hit their area. Having a place to go, even something as crude as ducking into a closet and dragging a mattress over yourself, can provide enough shelter to get you through a tornado because your shelter only needs to last 10-60 seconds, after which the tornado has moved on. (Obviously, being under something like a heavy workbench in a basement is even better). So some people probably were saved by advance warnings. And, of course, most people living between the Appalachians and the Rockies have some knowledge of what to do in the event of a tornado, and some idea of where local shelters are. The death toll could have been higher.

This thread has so far been about the tornadoes - this storm system has also produced hailstones the size of golf balls or bigger, and enough rain to cause severe flooding. The Mississippi is rising and Cairo, Illinois' floodwalls and levees are leaking - if they give way, the town will flood 6-7 meters deep. Most people there have already evacuated as a precaution, it's now described as a ghost town. Across the big river in Missouri farmers are also packing and leaving, for fear their homes as well as their fields will soon be underwater. The Federal courts and Army Corps of Engineers are currently debating whether to blow up the floodwalls and levees on one side of the Mississippi, definitely destroying one community, in order to save the other... with no guarantee that it will work. Parts of the Ohio river are expected to crest 19 meters above flood stage by Saturday.

There have been additional deaths from storms today in Virginia and New Jersey - same system, just moved on further east.

A lot of the above would normally make the news, it's just that the Tuscaloosa Tornado has eclipsed the rest of the severe weather currently going on.

[Broomstick]

And... another video of the Tuscaloosa Terror.

- At 2:38 the people filming roll their vehicle window down and you can hear the sound of a tornado, if you ever wondered what one sounds like.
- As the video continues you can see debris clouds appear and disappear around the mall across the street.
- 3:40 you can see the lights go out in the shopping mall. They blink back on briefly before going out again. Rain, wind, and debris fly by.
- 4:02 the ambient light takes on a green cast - when someone talks about a green tornado sky that's what they're talking about (it can actually get even more distinctly green than that).
- 4:12 the sudden jump in roaring noise is the tornado - needless to say, they are really too close for safety.
- 4:24 you get a good look at where the tornado actually makes contact with the ground, which is rare to see because most people aren't so fucking stupid as to stay that close when there is a means to flee or get under cover.
- The subsequent shuddering of the image is probably from their vehicle being slapped by the high winds near the tornado.
- 6:23 you can spot the crack in their windshield, as apparently they took a few debris hits.
- 6:35 you can hear "oh shit" in the audio... not sure if that's "oh, shit, it's fucking dangerous here" or "oh, shit, there's a fuckton of damage out there". Maybe a little of both.
- 6:50 you get another look at grey-green sky effects, the windshield crack, and you can see just how close they were to the actual ground track of the tornado.



One thing about this hitting urban areas - the weather guys now have LOTS of video to analyze. Believe me, they'll be looking over all of it.

[Johonebesus]

We were very lucky. The tornadoes barely missed our area. Two passed through just a few miles to the south. The nearby town of Cave Spring was hit hard. The north/west side of Rome suffered some. Redmond hospital lost some windows, and several trees fell, blocking roads and bringing down electrical lines. Luckily the south side of Rome, right between the areas of bad damage, was largely unscathed. Of course, just a couple of weeks ago another bad storm brought down a few trees, cutting off two of the main thoroughfares and taking out electricity in our neighborhood for almost twenty-four hours. Still not nearly as bad as in Alabama, but it sure wasn't fun last night.

All this bad weather is really beginning to worry me. My grandmother did not choose this house well. It has no basement and big windows in all the rooms. The oven is electric, so when the power goes out we can't cook anything. It's a little brick house designed for central air conditioning. Without electricity the house will become unbearably hot, which is a real problem for my grandmother. Then there is her oxygen concentrator. We have an emergency tank, but it won't last several days, and if the roads are trashed the provider might not be able to get out here.

[Sea Skimmer]

If you’re really seriously concerned about her O2 supply, you could get a generator to power the concentrator in an emergency. You can get a 1000 watt generator for about 120 dollars; but of course it won’t do you any good unless you test it regularly and keep a useful supply of fuel around. I don’t know how much power you need for one of those machines but 1,000 watts is likely enough. It could also power a fan to keep her cool. I don't know how long the concentrator needs to function, could be enough to require a lot of fuel, but the point of course is to extend the time you can last, not to be able to last an unlimited period. Stocking another spare bottle or two might also be an option.

However from what I’ve been reading, while the US just got an utter swarm of tornadoes, the number of days with tornado spawning weather in the US is actually on the low side for 2011. So this may just be a really bad day. I certainly hope so. As exceptional as this is, the fact is we don't have that much reliable weather data to go off of in history, stuff like this may be once in several lifetimes.

[Johonebesus]

With her fixed income and high medical medical expenses in a time of inflation, a couple of hundred dollars for a generator plus gas (which keeps going up) is not something we can easily afford. I've been thinking about it, but it wouldn't be an easy purchase.

To answer your question, a concentrator runs continuously. Patients don't get big machines to fill tanks, just small units with a line running from the nozzle to the patient's face. Then of course she has her nebulizer treatments that she needs several times a day. The nebulizer pipe can run off of a tank set to eight lpm or higher, but then that uses up her back-ups faster. She also uses a bi-pap, and if she goes without it (or refuses to wear it), the CO2 starts to build up in her blood. After a few days she gets very weak, and soon it will get dangerously high. Back when she would not wear the mask at night, she was going to the hospital about every six weeks. A generator might help us hold out for a day or two longer (depending on how much fuel it needs), but if the power goes out for more than a week, she'll be up shit creek.

[Broomstick]

However from what I’ve been reading, while the US just got an utter swarm of tornadoes, the number of days with tornado spawning weather in the US is actually on the low side for 2011.

We may have had fewer "tornado spawning days" but those we've had have been doozies - even before this week we had set an all time record for number of tornadoes in April. Fewer days to generate them, but more overall than we normally would have gotten by this time of the year.

May is usually peak tornado month... but I hope this year is an exception.

[Sky Captain]

How probable it is that your house will be hit by tornado if you live your entire life in Tornado Alley? Is it something more likely than your house accidently burning down?

[Serafina]

How probable it is that your house will be hit by tornado if you live your entire life in Tornado Alley? Is it something more likely than your house accidently burning down?

Even if the risk is lower than your house burning down: It's an additional risk.
Saying otherwise would be like saying "oh i already have lung cancer, stomach cancer poses no additional risk to me".

[Broomstick]

Many more houses burn than are hit by tornadoes, and not every house that gets a tornado is destroyed - most tornadoes are in the EF0-EF1 category which, with a well built structure, means a damaged roof and likely more problem from falling trees and flying debris than the tornado itself. The ones that went through the South this week were in the more powerful EF4-EF5 categories which... well, you can see for yourself.

The other thing to remember is that for all their violence and destruction tornadoes are, in a sense, very localized. You can have one building destroyed down to the foundation and the one next to it intact. When I was still living in St. Louis as a very young child we had a tornado go down the street we lived on and it took the roof off every second house on the block. Our home was undamaged, but our neighbors to either side had to get their roofs put back on.

Then again, what goes up must come down, so you may be some distance from the tornado's ground track but get your house showered with debris falling out of the sky. One of the people interviewed by the news in Alabama said that even before the sirens went off they knew something was up because branches and entire trees were falling out of the sky.

Most people who live in Tornado Alley will never directly experience a tornado, but they will know or be related to someone who has. They are rare events, but so dangerous that it is well worth keeping the public informed, building shelters into buildings, and so forth. Places like trailer parks, where the housing isn't very substantial and prone to destruction in such storms, are in some places required to build strong masonry storm shelters of sufficient size for everyone in the community to take shelter during severe storms. It's also becoming more common to build "safe rooms" into homes that are sufficiently strong and anchored to keep people safe during even the most powerful tornadoes.

At this point the question usually comes up why not build everything that strong. Well, it's because people don't want to live in concrete bunkers with tiny windows. There are buildings in even the most tornado prone areas that are a century or two old, and it's not economical to build everything to that standard. Most buildings will be torn down or replaced for other reasons long before a tornado hits them.

[Broomstick]

Here is an interview with a family that had a safe room. Their house was completely destroyed but they were safe.

[Crossroads Inc.]

I know this may seem crass... But why, in all of this time, have people not at some point tried to build underground homes, and not just underground shelters?
I mean, perhaps someone has tried it in the past, and maybe it wasn't commercially viable? But, you would think in a place like "Tornado Alley" there would be a market for underground homes.

[Rogue 9]

There are a few, but as stated already in the thread, tornadoes are sufficiently rare that it's not worth living in a bunker out of fear of them. That stated, I would never live in a house without a dug-in basement, and I'm not even in the most tornado-prone section of the midwest.

[Broomstick]

Storm cellars are the traditional underground bunker for severe storms and tornadoes, and the wiki on them is a reasonable article. Until the arrival of the modern safe room they were the only reliable way to ride out an EF4 or EF5 tornado. However, not all areas are suited to building them. Where I live, for example, the water table is so high that there wouldn't be a reliable way to keep them dry, and given that the type of severe storms that generate tornadoes also tend to produce flooding in my area it's sort of choice between death by debris and death by drowning. Sure, you can build a sump and keeping pumping it out, that's how people who do have basements around here (which are generally only about half underground when they do exist) keep them "dry", but as soon as the power goes out the water rises. And what else is associated with these storms? Power outages.... Actually, power failures and flooding are both far more common than tornadoes in my region.

In early settler days people did build underground homes of a sort, the prairie "soddy" but even those were usually no more than half below grade and they didn't last as long as wood or stone.

Even where geography would made underground homes practical there is a LOT of cultural resistance to it. And really, that's the bulk of the reason, cultural resistance. Which is a shame, as they do provide very nice protection and fuel efficiency.

[Sea Skimmer]

Something like an Anderson shelter bermed over above grade level would work almost as well as a buried shelter against a tornado, given a good enough steel door. But the berming means it would take up a lot extra land area. Not a big deal on many rural properties but it could become an issue in suburbs and simply not an option in cities. This problem of course wouldn't exist by now if we hadn't abandon the 1950s campaign to give everyone a bomb shelter. As the Swiss have showed you can well protect your whole population from 40psi atomic blast at sane cost, in comparison 500mph wind generates about 20psi of overpressure. I forget what 40psi is but I think its in the 750mph range. So you'd only be left worrying about those pesky supersonic tornadoes!

A lot of existing safe rooms are not proof against an EF5 tornado as they are reinforced cinder block masonry which can be broken up by hard enough debris hits. The newest ones are made of quarter inch steel or reinforced concrete and will survive any possible storm wind (and rifle bullets) if anchored sufficiently, but this standard of protection is pretty new. I believe in some states you now legally can't call something a safe room if it won't stop an EF5 but its not universal.

[Broomstick]

Keep in mind that an EF5 is rare, even by tornado standards, and safe rooms typically are within/in the center of/in the basement of a surrounding building which will blunt some of the debris hits (well, at least initially). It doesn't have to withstand extensive pummeling, just a few seconds worth. Ones rated for EF4's that are located centrally in a building or in a basement will probably also survive EF5's (it's just less of a guarantee)

[Broomstick]

Wasn't expecting this one - apparently the tracks are visible from space, at least if you're NASA satellite:

This one shows a storm track:


This is a before view, without the track:


And here's another one, where the track is a fairly obvious diagonal:

[CaptHawkeye]

I know it was addressed before but it still astounds me that people even want to live in regions like this. It may be less likely to happen than your house burning down but still, it's just another item on the list of likely events that could destroy your home.

Still, I'm open to the idea that the media sensationalizes tornadoes and their frequency/power a lot.

[Broomstick]

Uh... the "region" in question consists of about half the land area of North America.

Really, the broadest definition of Tornado Alley is "everything from the Appalachian Mountains to the Rockies", and extends from the Gulf of Mexico up into Canada. Even more narrow definitions still take up about 1/4 to 1/3 of the continent. That's quite a bit of territory to declare off limits.

It's also somewhat like saying "Why do people live in Japan with all the risks of volcanoes, earthquakes, and tsunamis?" Well, I guess because in between the catastrophes the living is actually pretty good there.

The US does get more tornadoes than anywhere else in the world, that's a fact. Most of them aren't this bad, but that's no consolation to those who have suffered from the recent outbreak.

[Ariphaos]

It's a bit like asking why people live in hurricane-prone areas, regions with active volcanic or tectonic activity, regions with tsunami risks, flood-prone regions, or regions with wildfire risks...

...at some point, you have to pick somewhere to live.

[Sea Skimmer]

The death toll has been revised to 337 at last count.

[The Duchess of Zeon]

Brown's Ferry successfully shutdown and it will be several weeks before it resumes operation. Obviously since everything worked like it supposed to you don't hear a peep about it out of the media unlike Fukushima.