Is it time for those in common hurricane paths to fend for themselves?

Great Debates
21

Only vaugely joking. Assuming a wide flat area, with, say, a random hill to one side or another, maybe near a highway, it seems fairly plausible that winds would be directed towards it by the natural shape of the land. You know, very few mobile homes are more than one story tall, and there’s a lot of them in one location.

I’ve done some flying in gliders, and I admit that I havn’t flown over any mobile home parks, but I did visit a few in Florida in the 90s. Now, the ones in other states may vary, but I’d expect the thermal characteristics to be similar to, but lesser than, a parking lot. Parking lots generate strong updrafts.

And that’s why I wonder if they could be attracting tornadoes. I’m not talking about poverty or anything else, I’m thinking about landscaping and weather patterns.

Anyone got a solid bit of evidence to throw one way or another?

22

It’s just that the tornados don’t hit mobile homes any more frequently than they hit anything else. Yes, people joke about it frequently but there isn’t any truth to the idea that tornados hit them more than anything else.

23

You are throwing out some complicated ass explanations for a very simple problem. Tornados and hurricanes don’t hit trailer parks any more than other housing area of the same size. It is simply that when they do get hit, they get damaged or destroyed much more easily than stick or brick housing. News crews love maximum devastation so that is what is always shown.

24

A slight hijack here -

After we got hit by a hurricane I had the opportunity to speak with the local Building Commissioner. He remarked that a number of older homes had weathered the storm better than new homes and one of the reasons actually had to do a seemingly benign piece of technology - the nail gun.

Nail guns put nails in perpendicular to the equipment being nailed. Humans using a hammer will put nails in at angles and a variety of spacings. The nails driven by humans do better at holding the materials together.

Interesting.

25

I never said I was trying to explain anything. I always figured the trailer park bit was a joke, as much as anything. Then I thought about it for a moment, and said, “Well, what if?” I mean, there’s no reason to dismiss the hypothesis out of hand, is there?

26

I don’t think there’s a reachable formula for FEMA assistance based on a natural threat/locale formulation but a simple groundrule I’d like to see imposed would be that monetary assistance could only be given to rebuild primary residences. When taxpayers are burdened with the cost of repairing second or third beachside homes of the wealthy then some kind of reform is due. (I’m assuming this isn’t already the case.)

27

Experienced Glider pilot here. I was also raised on a hill top to the northreast of Denver with a good view of the eastern plains, where we got to watch twisters a couple of days each summer…pretty much where they decided it would be a good idea to build DIA. My hometown was struck by several tornados in the early June of '81, and I watched one of them form over my head.

There is something to what E-Sabbath says regarding thermals, which ARE NOT tornados.

The sun pretty much doesn’t heat air at all. The sun heats the ground, and the the ground then transfers that heat to the layer of air next to the ground.

For a good thermal, you want that warm air to stay next to the ground until a fair amount of it has built up. A bit of shelter from stray breezes is really helpful. Eventually some of it breaks off, and disturbs the nearby area, causing a domino effect.

This is aided by lots of buildings, parked vehicles, holes etc. Examples: Large truckstop parking lot, dry gravel pits, Automotive junk yard School bus parking yard. Highschool campus…and yes mobile home parks.

While a thermal might trigger a tornado under appropriate conditions, all of the tornados and funnel clouds I have observed (probably over 30) began well above ground level, eventually reaching the ground or not. Thermals, conversly always start at ground level. Tornado conditions require a thick layer of light warm air being trapped under a layer of cool heavy air. The tornado thus “starts” at the interface between these two layers. The thicker the lower layer, the more power is trapped, but the higher the tornado will start.

In order to touch down, the hot air needs to “drain” upward, locally thinning the hot layer until it reaches the ground. At that point the tornado pretty much has to move or die, as it has locally depleted it’s energy source.

So why do moble homes seem to attract tornados?

-They tend to be packed into mobile home parks having minimal lot sizes. Covering the same area, a tornado’s path might take out 30 houses or 100 mobile homes. Much of tornado ally is rural, with only scattered farmhouses, but still with the odd trailer park…in this case the disparity is much greater.

-It doesn’t take a tornado to rip up a mobile home. Boulder,CO has strong canyon winds. Prior to mid '70s these would take out a few mobile homes every year. No, the winds didn’t stop coming, but the city of Boulder inacted standards for tying down mobile homes. There are high winds outside the funnel of a tornado. While a standard home might survive all but the funnel itself, The track of mobile home damageing winds is perhaps 10 times wider.

-Mobile homes don’t have basements. Thus there is no ready-made shelter from the storm. So when a mobile home park gets hit there are disproportionatly more fatalities, attracting more news coverage.

28

Surprisingly well? What’s so surprising about it? I mean, that was why the codes were implemented!

29

I got distracted before I made one major point I was aiming for:

If a mobile home park generated thermal were to trigger a tornado at the mobile home park, it would require absolutely calm wind conditions.

Thermals drift downwind as they rise. A strong thermal will be perhaps 10 kt. Even a very mild 5 kt. breeze will thus cause the thermal to “lean” at a 30 degree angle from vertical. If the boundry between air masses were at 4000’AGL, then the funnel would form about half a mile downwind from the thermal source. The funnel would then drift yet farther downwind before it reached the ground.

30

Specifically, I was wondering if the existing thermal, which draws air upwards, might act like a… drain, say, to draw air, and by extension, an existing tornado, towards the park.

But thermals only really form in still air, anyhow, don’t they? So… Well. One of those random thoughts, worth tossing around, but not large enough to be a significant factor.

31

Now back to the OP.

Is denying federal aid to major cities that get hit by hurricanes a good idea? How about people who have the audaucity to build on a fault line? Or even people who live in tornado alley.

Never mind that the odds of actually being hit by a tornado are very small. I lived in Oklahoma for 30 years and only once did a tornado come close enough to see it. (althogh the big one a few years ago did come close to my sister)

The fact is that spending these billions of dollars on to rebuild after natural disasters is good for the entire country.

32

Only because we haven’t had a major quake in a few years. Next time we get a good shake, you’ll be hearing plenty of people saying exactly the same thing about California. It’s a dumb idea, no matter how you slice it. $70 million in disaster relief to North Carolina? Sounds bad, but how much revenue has NC added to the national coffers between hurricanes? I can pretty much guarantee it’s a net gain in the long run.

33

This is what makes the premise of having people living in "risky"areas fend for themselves so ridiculous. You’d have 250 million people living in a small town in Nevada (or is there a faultline there too?). Just for the hurricanes alone you’d have to evacuate huge sections of the east coast and the gulf, 90% of which are probably never going to see significant damage from a hurricane anyway.

34

As in, “we expected improvement, but not that much of an improvement”. We tend to be mildly pessimistic about “problem solving” here in the tropics. That way we can be pleasantly surprised that things turn out moderately well, as opposed to bitterly heartbroken to fall short of expectations of excellence. :wink:

(And in any case, tropical or non-tropical, engineering solutions often have a way to NOT behave as expected when faced with real-world conditions. Ask the guys who spent the last 2 years “solving” NASA’s insulation foam issues. :smack: Goes double for homebuilding, where you can’t really be sure every single structure followed the plan to the letter, and a huge fraction of new houses has some construction defect at delivery day.)

35

I’m sure the idea of mandatory “disaster” insurance has been floated before as a solution to this sort of problem. What are the problems with it?

Brian

36

And the Southwest has brush fires that destroy homes.

37

Yes everywhere has disasters, but we are talking different beasts. I posted the relevent information about the costs with hurricanes compared to everything else. Clearly hurricanes cause more damage then anything else.
Now earthquakes may rank way up there, but I do not see them rebuilding on the major fault lines if the “big” one hits, as the dead would not care about rebuilding. Of course thats only my opinion and I am most certainly not a geologist
As for rebuilding New Orleans, that is stupid IMHO. But I know I am not alone I have heard more then one member here say that as well as people elsewhere. If anything bulldoze the whole city haul in thousands and thousands of tons of dirt and built the damn city up higher about sea level.
My meeting opponents half way proposal is raise the level around the port, port employee’s only allowed. Month on month off work. No families on site, no personal homes on site. But keep the levies in place and the historical homes for tourist visits.
Of course if you want to keep your land thats fine, you can build your house on stilts, or underwater who cares, but don’t ask for help when it happens again.

There is plenty of land above sea level for them to rebuild on with government help. I am willing to make concessions on my original thoughts, but I cannot be swayed on New Orleans being rebuilt. Unless they fill the “bowl” above sea level.

38

Seems this pit thread may be relevant to a few posters here.

39

I don’t know what they’d have to do to ensure the safety of the city, but a world without Congo Square, Preservation Hall, and Commander’s Palace is no kind of world in which to live.

40

Some skycopter footage worth checking out

WLBT Skycopter footage of Mississippi Coast