Tornado sirens

[LosMediasBlancas]

From what I understand, yes. The landscape of a city has little to do with the weather. For example, St. Louis and the surrounding area had had numerous tornadoes, some quite large. Brooklyn also had a tornado last year and Atlanta had one this year as well..

 

I realize that landscape would have no effect on heat, rain or snow, but we're talking about wind here. I've always heard that buildings, especially tall ones, would break up the wind and not allow it to reach tornado strength.

Interesting info, thx.

[Flash Tizzle]

I'm fairly sure Lake Michigan plays a significant role in the lack of tornados around the Chicagoland area. The cold pressure systems off the lake usually dominate the warmer air from the West/South and it prevents the circular patterns required for funnel clouds.

 

There was a F4 tornado in Oak Lawn 40 years ago that many of our parents, if they lived around the south suburbs, probably remember. Haven't been any around here since, so they're rare -- but possible.

Edited August 5, 2008 by Flash Tizzle

[southsider2k5]

We have the sirens go off a few times year out by us in Michigan City. They went off last night, and we had 100 mph winds and damage to the casino. It was crazy.

[NorthSideSox72]

I'm fairly sure Lake Michigan plays a significant role in the lack of tornados around the Chicagoland area. The cold pressure systems off the lake usually dominate the warmer air from the West/South and it prevents the circular patterns required for funnel clouds.

 

There was a F4 tornado in Oak Lawn 40 years ago that many of our parents, if they lived around the south suburbs, probably remember. Haven't been any around here since, so they're rare -- but possible.

I don't know the exact nature, but yes, its definitely true that the lake has a dampening effect that makes tornadoes near the lake rare. Not impossible, however. A number of years ago, a weak tornado (weak as tornadoes go - still a powerful event) went through part of Wilmette, went out over the lake, and turned into a water spout.

 

[StrangeSox]

That was one hell of a storm last night. When the lighting was first starting up, it was turning the sky a bright turquoise color. I've never seen anything like it.

 

There were funnel clouds in Elmhurst and Lemont, so it seems like they went right around us.

Edited August 5, 2008 by StrangeSox

[Steve9347]

That's a top notch setup right there. And of all places to go in a natural disaster, why not come to Soxtalk?

Exactly.

[BobDylan]

Cause what you are going thru now happens a few times every year here in Eastern Iowa.

 

So do you guys go to the doorway and watch it storm too?

 

Sure, the tornado sirens are going off, but I'm gonna look out the door and check to see what all the fuss is about.

 

The buildings in Chicago protect the city from tornadoes. It's not impossible for a tornado to hit, but it'd be very rare. The sirens in Chicago have only gone off a few times since their existence. They only run them in the most extreme cases and when the White Sox win the '83 Pennant.

Edited August 5, 2008 by BobDylan

[BobDylan]

I don't know jack about tornadoes, I was being serious, but let me make sure I understand. For the sake of argument, let's say that Topeka, Kansas is the area in the U.S. that is most prone to tornadoes. If Manhattan had been built where Topeka stands today, that area would be equally prone to tornadoes??

 

No. The Manhattan skyscrapers would protect the city. Outside area's would be prone. It wouldn't be impossible, but the tall buildings do in fact protect the cities. The sirens went off one or two years ago in the city and I remember watching Tom Skilling talk about it. It'd take a tornado of the most damaging proportions to build in a city like Chicago or NYC, but it can happen. The buildings, though, generally fend off the weaker threats that hit places like Topeka.

[NorthSideSox72]

The buildings in Chicago protect the city from tornadoes. It's not impossible for a tornado to hit, but it'd be very rare. The sirens in Chicago have only gone of a few times since their existence. They only run them in the most extreme cases and when the White Sox win the '83 Pennant.

Ugh.

 

First, the sirens went off in '59, but not '83, because it caused a panic in '59.

 

Second, the buildings do NOT stop tornadoes, as was pointed out earlier. The reason tornadoes are less frequent in the city is the same reason they are less frequent in the suburbs along the north shore - the lake. For example, a few years ago a big tornado ripped through downtown Dallas (or was it Fort Worth), and tore up a lot of those big buildings.

 

Third, they go off whenever their is a tornado warning. That's rare, but not "a few times in their existence".

[RockRaines]

It would take a hell of a lot to take down some of these brick buildings downtown as compared to the double wides and pre-fab hopmes they destroy on a constant basis in other areas. If it was a powerful tornado however, Chicago could be devastated by a storm like that.

[BobDylan]

Ugh.

 

First, the sirens went off in '59, but not '83, because it caused a panic in '59.

 

Second, the buildings do NOT stop tornadoes, as was pointed out earlier. The reason tornadoes are less frequent in the city is the same reason they are less frequent in the suburbs along the north shore - the lake. For example, a few years ago a big tornado ripped through downtown Dallas (or was it Fort Worth), and tore up a lot of those big buildings.

 

Third, they go off whenever their is a tornado warning. That's rare, but not "a few times in their existence".

 

My mistake on the year. Do you want to debate with Tom Skilling? Go "ugh" him, Mr. Admin. Also, I never said the buildings prevent tornadoes. Reading is a skill. And they don't go off for all warnings. I lived many years in the suburbs and have seen many, many tornado warnings that weren't accompanied by a tornado siren.

[BobDylan]

It would take a hell of a lot to take down some of these brick buildings downtown as compared to the double wides and pre-fab hopmes they destroy on a constant basis in other areas. If it was a powerful tornado however, Chicago could be devastated by a storm like that.

 

A tornado wouldn't take most of the buildings down -- I'm talking about the Loop ilk of buildings. It would, however, damage some beyond repair. The structures are too strong to just topple over or crumble from a tornado. But I wouldn't expect to see too many windows after it.

[NorthSideSox72]

My mistake on the year. Do you want to debate with Tom Skilling? Go "ugh" him, Mr. Admin. Also, I never said the buildings prevent tornadoes. Reading is a skill. And they don't go off for all warnings. I lived many years in the suburbs and have seen many, many tornado warnings that weren't accompanied by a tornado siren.

 

Right here, Mr. Poster:

 

The buildings in Chicago protect the city from tornadoes

 

Quoting is a skill.

 

And they do go off for all warnings unless there is a malfunction - that is their purpose at the present time (they were originally around for air raid use, actually). They go off in the path of the storm of course, not everywhere in any given county necessarily.

 

[BobDylan]

Right here, Mr. Poster:

 

 

 

Quoting is a skill.

 

And they do go off for all warnings unless there is a malfunction - that is their purpose at the present time (they were originally around for air raid use, actually). They go off in the path of the storm of course, not everywhere in any given county necessarily.

 

Anyone can take a statement out of context. How about you read the sentence directly after it?

[NorthSideSox72]

Anyone can take a statement out of context. How about you read the sentence directly after it?

I'll take NOAA's word for it that buildings are irrelevant:

 

Why does it seem like tornadoes avoid downtowns of major cities? Simply, downtowns cover such tiny land areas relative to the entire nation. The chance of any particular tornado hitting a major downtown is quite low -- not for any meteorological reason, but simply because downtowns are small targets. Even when tornadoes hit metro areas; their odds of hitting downtown are small out of space considerations alone. For example, downtown Dallas (inside the freeway loop) covers roughly three square miles, Dallas County, about 900 square miles. For a brief tornado in Dallas County, its odds of hitting downtown are only about 1 in 300. Still, downtown tornadoes have happened, including at least four hits on St. Louis alone. The idea of large buildings destroying or preventing a tornado is pure myth. Even the largest skyscrapers pale in size and volume when compared to the total circulation of a big tornado from ground through thunderhead.

[BobDylan]

I'll take NOAA's word for it that buildings are irrelevant:

 

While that is relevant, it's utterly non-scientific and more a matter of coincidence than anything. The buildings DO offer an amount of protection (to prevent you from taking this out of context, I don't mean that the buildings entirely prevent tornadoes.) There is an effect called "heat island." This means that air has less room to spread outward, therefore it's forced to move up (and high enough in the cases of major metropolitan areas), thus disrupting the formation of tornadoes. Unfortunately, I've only seen this on the Discovery channel so I can't provide a link. I'll search around for a reference.

[kapkomet]

Ugh.

 

First, the sirens went off in '59, but not '83, because it caused a panic in '59.

 

Second, the buildings do NOT stop tornadoes, as was pointed out earlier. The reason tornadoes are less frequent in the city is the same reason they are less frequent in the suburbs along the north shore - the lake. For example, a few years ago a big tornado ripped through downtown Dallas (or was it Fort Worth), and tore up a lot of those big buildings.

 

Third, they go off whenever their is a tornado warning. That's rare, but not "a few times in their existence".

It was Fort Worth in 2000. They just opened the tallest skyscraper that the tornado hit back up last year after 7 years. They worked on that thing forever.

 

 

[Disco72]

The tornados that hit downtown Atlanta didn't knock down any skyscrapers, but they are still replacing windows several months later. The Westin hotel (one of the tallest buildings in Atlanta) looks like a checkerboard.

[LosMediasBlancas]

I'm sorry I asked, Sheesh. and I'm still confused.

[NorthSideSox72]

While that is relevant, it's utterly non-scientific and more a matter of coincidence than anything. The buildings DO offer an amount of protection (to prevent you from taking this out of context, I don't mean that the buildings entirely prevent tornadoes.) There is an effect called "heat island." This means that air has less room to spread outward, therefore it's forced to move up (and high enough in the cases of major metropolitan areas), thus disrupting the formation of tornadoes. Unfortunately, I've only seen this on the Discovery channel so I can't provide a link. I'll search around for a reference.

Are you seriously saying that your hazy memory of Tom freakin' Skilling is correct and that NOAA is "utterly non-scientific"? Really?

 

[BobDylan]

Are you seriously saying that your hazy memory of Tom freakin' Skilling is correct and that NOAA is "utterly non-scientific"? Really?

 

Do you read one sentence then stop? Am I imagining what I am typing? Am I everything so poorly that they aren't getting across to you? Tell me what's wrong. The post you quoted had nothing to do with Tom Skilling. The previous posts did, but not that one. The quote you have from the NOAA talks about chance. You don't think there is a reason the tornadoes generally hit the outside areas of the city more than the central downtown area? Or are you just going to dismiss it as pure chance because the NOAA told you to?

 

Jesus, god forbid anyone to challenge the NOAA, especially the University of Chicago professor who thought up the theory I tried to present you. But I'm such an idiot, as I can tell by the tone you've taken with me since reply one, that anything I say is just pure stupidity. I'm nothing but "ugh," there he goes again. Do myself, yourself and everyone a favor before I say what I really want to say and lose my membership: DROP IT.

Edited August 5, 2008 by BobDylan

[NorthSideSox72]

DROP IT.

OK.

 

[BobDylan]

And here's your damn reference:

 

"History shows that tornadoes can hit big cities. You will find a map showing the paths of all of the tornadoes to hit the Chicago area from 1876 through 1995 in the book U.S. Tornadoes, Part 1, 70-year Statistics by T. Theodore Fujita, published by the University of Chicago in 1987. Fujita, for whom the 1-5 tornado ranking scale is named, was at

the University of Chicago from 1953 until he died in 1998.

 

If you are in the Chicago area, you should be able to find a copy of the book in a local library, or — I certainly hope — in the university's library. In it, he notes that: "Since 1921, practically no tornadoes occurred or moved across the central portion of Chicago." He says some have speculated that the city's heat-island effects (the fact that cities are warmer than surrounding areas), and man-made structures "are acting against any tornado activity over the city." But, as the tornadoes that have hit other cities have shown, the heat or buildings of a city can't guarantee that it's safe from tornadoes"

 

 

 

 

 

 

[whitesoxfan101]

The city of Chicago itself is very unique in terms of weather, which is probably why you don't see tornadoes there. The lake keeps the city cooler than the surrounding area in many cases, as is the case throughout areas of Lake County as well. But the difference is Chicago isn't cooled nearly as much by the lake as places like Waukegan can be because of the urban heat island affect in the city re-warms the area a bit. For example, you'll often see a day in July where it's 78 in Waukegan and 88 in Aurora, but 83 in Chicago itself. Chicago is as complicated weatherwise as any city you'll find in the country, it's really hard to explain the weather in the city as it can be very different than even the nearby suburbs. One thing I will say is the reason the loop hasn't had a major tornado in well over a century has nothing to do with the tall buildings or the fact it's a big city. All the tall buildings really do is aid the urban heat island affect (but so do a lot of things, like the blacktop streets and emissions from automobiles). Actually, one other thing the tall and tightly packed together buildings can do in a downtown area during the storm is make the winds stronger and especially more likely to swirl.

Edited August 6, 2008 by whitesoxfan101

[LosMediasBlancas]

The city of Chicago itself is very unique in terms of weather, which is probably why you don't see tornadoes there. The lake keeps the city cooler than the surrounding area in many cases, as is the case throughout areas of Lake County as well. But the difference is Chicago isn't cooled nearly as much by the lake as places like Waukegan can be because of the urban heat island affect in the city re-warms the area a bit. For example, you'll often see a day in July where it's 78 in Waukegan and 88 in Aurora, but 83 in Chicago itself. Chicago is as complicated weatherwise as any city you'll find in the country, it's really hard to explain the weather in the city as it can be very different than even the nearby suburbs. One thing I will say is the reason the loop hasn't had a major tornado in well over a century has nothing to do with the tall buildings or the fact it's a big city. All the tall buildings really do is aid the urban heat island affect (but so do a lot of things, like the blacktop streets and emissions from automobiles). Actually, one other thing the tall and tightly packed together buildings can do in a downtown area during the storm is make the winds stronger and especially more likely to swirl.

 

 

"...Actually, one other thing the tall and tightly packed together buildings can do in a downtown area during the storm is make the winds stronger and especially more likely to swirl."

 

How exactly?