Thousands could die if a giant tornado ever hits Ho

[jasons2k]

Notice how they got the numbers; it's probably an overestimation.

Something that I did not realize - and was very surprised to find out - was that Houston does not have a siren network. That's SCARY. After living in the DFW area for so long, I just took sirens for granted. They NEED to fix this.

Someday, after a major tornado hits and there is an outcry to build a siren network (after the fact) dig this thread up.

Here is the article from the Chronicle:

http://www.chron.com/disp/story.mpl/front/4564928.html

Feb. 20, 2007, 12:48AM
Thousands could die if a giant tornado ever hits Houston
Experts say toll might surpass the 8,000 of the Galveston Hurricane of 1900

By ERIC BERGER
Copyright 2007 Houston Chronicle

Houston is south of "tornado alley," which centers on Oklahoma. But Houston isn't immune from tornadoes.

As recently as November 1992, six tornadoes formed during a series of thunderstorms, one of which reached F4 status, the second-strongest category, in which cars are thrown like missiles and homes are leveled.

Spinning at 225 mph, the tornado touches down in southwest Houston, skirting the Astrodome and barreling through parts of River Oaks, Montrose and the Heights before exiting the city's northeast edge.

At the end of its run, the tornado will have killed as many as 23,700 people whose residences and business cannot withstand the deadly wind.

That's the conclusion of severe storm researchers using new data to model the effects of large tornadoes striking U.S. metropolitan areas such as Houston, Chicago and Dallas. The researchers say there is little data to know for sure how many people would die in urban structures in a large tornado.

Tornado warnings
The average number of tornadoes in Harris County is 6.4 times above the overall U.S. average, and more tornado warnings are issued in this county than in any other.

"These are indeed unlikely events," said Joshua Wurman, president of the Center for Severe Weather Research in Boulder, Colo., and lead author of a recent article in Bulletin of the American Meteorological Society on the tornado modeling.

"But I think, given the consequences, it's prudent for emergency managers to think about what they would do if such a thing happened."

Such a thing has never happened in Houston. But if it did, it could become the deadliest natural disaster ever to strike Texas, perhaps even eclipsing the 8,000 dead from the Galveston Hurricane of 1900.

With a hurricane, people have advance warning, and the gridlock associated with Hurricane Rita aside, generally can get out of the way.

The warning time for tornadoes, is measured in minutes rather than hours or days. The average tornado moves at about 30 mph.

Because the odds of a killer tornado are relatively remote, Houston emergency planners are correct to focus their efforts on hurricanes rather than tornadoes, said Bill Read, meteorologist-in-chief at the Houston/Galveston office of the National Weather Service.

"It is challenging enough for those in emergency preparedness to get people to be concerned about floods and hurricanes — both of which have a proven track record in our city for taking lives and destroying large amounts of property, without specifically going after a long-track F4 scenario," he said.

The worst U.S. death toll from a tornado is 695, killed when the "Tri-State Tornado" tore through Missouri, Illinois and Indiana in March 1925.

No sirens
Unlike some communities, Houston has no network of tornado sirens. Residents seeking warnings, however, can get a NOAA Weather Radio, which sounds an alarm tone when a severe threat is imminent.

To determine the number of deaths in a tornado strike, the researchers estimated that 10 percent of people, with little advance warning, would die in destroyed structures.

"The important caveat to realize is that we are very crudely estimating those deaths," Wurman said.

Other tornado experts, including Harold Brooks at the National Severe Storms Laboratory in Norman, Okla., said that 10 percent figure is probably too high.

During the 1999 tornado outbreak in Oklahoma, the most powerful tornado killed about 1.7 percent of residents in the hardest-hit areas, Brooks said. Those storms left 48 dead.

He also noted that the storms used in the research paper have the highest intensity and widest diameter of known tornadoes, representing a truly worst-case scenario.

"I think the estimates are too large by at least an order of magnitude, more likely closer to two orders of magnitude," he said.

Wurman noted, however, that residents of Oklahoma had an unusually long warning time, so many had fled the area before the storms reached the area.

Of the cities studied in Wurman's paper, Chicago was found to have the highest potential death total, 60,000, and Dallas, with 29,700, also had a worse worst-case scenario than Houston.

The new modeling represents the first time scientists have succeeded in gathering tornado wind-speed data just 10 feet above the ground.

"It's a very difficult place to study," Wurman quipped.

Chasing down data
In recent years, using Doppler on Wheels technology, storm chasers have begun measuring wind speeds above 50 feet, but interference with terrain has precluded measurements below that elevation. But to accurately model ground-level damage the scientists have needed ground-level measurements of wind speeds.

So Wurman and his colleagues strapped some meteorological equipment to an armored vehicle and drove into a moderately powerful tornado close to Jayton, near the Panhandle, during the summer of 2005.

They got a single measurement of winds there, and found the speeds were about 75 percent as strong as the winds at 60 feet.

They now are trying to get more measurements.

•Houston emergency planners focus more on hurricane preparedness than pm tornadoes given the likelihood of a hurricane.

•Meteorological equipment has allowed Oklahoma residents to have more than the average advance notice — enough to get out of a tornado's path.
The worst-case scenario for a large tornado striking Houston makes a hurricane look like high surf.

eric.berger@chron.com

[vbhoutex]

I understand the premise of concentrating on a Hurricane vs a Tornado due to the widespread destruction of a hurricane as opposed to a more pinpointed destruction with a tornado. Question I have though, to throw a caveat into this is-Have we had more tornados or hurricanes over the time records have been kept?

[southerngale]

Good question. Although I'm not in Houston, the same applies over here. Although we've had many tornadoes here, they weren't those giant ones, so the destruction of Rita (and even Bonnie in 1986, and of course TS Allison) far exceeds the destruction of any tornado. Rita's damage would far exceed the damage of all the tornadoes that I can recall all together.

But, I don't know of a giant tornado hitting here. That doesn't mean it can't happen although I've always assumed this part of the country gets the smaller ones. I've seen them turn houses into matchboxes, but the damage is more isolated than what I've seen in other parts of the country.

Most people thought all destructive hurricanes would turn and miss us as well, like they usually do...now they know better.

Btw, no sirens over here either.

[conestogo_flood]

We have no tornado sirens, no television cut-ins, no storm centre at the news station(also no experienced meteorologist), no weather radios(though there is a network), and a population that hardly notices weather.

We have tornadoes of F3 and F4, but none have hit any major cities yet. In fact, no major city has really been hit, and when one is(even if F1) it's not a news story.

I have emailed and called the county several times almost demanding a warning system and they feel it would be (paraphrasing) a waste of money to install one.

Last May we had a tornado warning during a power outage, and a funnel came 200 feet to the ground over the city and no one knew, even weeks after it happened.

I've told them repeatedly, once it happens they will wish they had a system. It will happen, and it's happened before. Environment Canada said in a report after the May 31, 1985 outbreak of tornadoes that they would work in part with Emergency Management Ontario and the public to develop a better warning system. Still waiting on that warning system.

[senorpepr]

Let me throw this into the mix... a siren network is NOT a good solution. If anything, it's a BAD idea.

Sirens create the illusion of safety. "Don't worry... you don't hear the tornado siren yet... so there's no tornado."

Now... I've lived in the Great Plains for a large majority of my life. I've experienced countless severe thunderstorms over the years, to include being under many tornado warnings. Usually, tornado sirens are a decent distance away. Right now, I'm rather lucky... I live about 1/4mi from the nearest siren. At times, I have been miles from a siren.

Even at 1/4mi, with the windows and doors shut, I can barely hear the siren. Now, add in heavy rainshowers, gusty winds, thunder, and hail, the siren cannot be heard.

Sirens are NOT made to protect individuals indoors--they are made for people OUTSIDE.

So, to stamp this into the ground, sirens provide a false sense of security. Too many people depend on a siren to warn them when sirens are not designed to warn people indoors.

I remember an event while living in Kansas City where people were outraged BECAUSE they had sirens... although they could NOT hear them when they depended on them the most. Bottom line, the best form of security is a NOAA weather radio. While I was living in KC, weather radios were pushed just as hard as smoke detectors. Come spring and come fall, it was time to change the batteries in BOTH the smoke detector and weather radio.

Regarding weather radios, people complain that they become annoying... alerting anything and everything, even if the storm is far away. Well... there ARE weather radios they allow the user to customize what alerts will sound and for what counties. If I wanted to, I can set my radio to ONLY alert me for tornado warnings in my county.

[jasons2k]

I'm not advocating a siren network as THE be-all solution, but it should be a part of the warning network. Nobody should depend on a single means of warning for protection, but it's good to have them. I know the sirens in the DFW area are pretty modern with voice/warning information actually read over the system, and cities such as Arlington have been in the news for spending money to upgrade their systems and provide better coverage.

I can also tell you that a lot of people in this area are from Dallas. Until today, I had no idea we didn't have sirens. This is the first place I've lived where we didn't have them. NOT hearing them would provide a false sense of security.

Furthermore, NOAA radio coverage in the 'burbs here is spotty at best. The transmitter for my area is in downtown Houston, some 30 miles away. Yes, according to the maps we're covered, but try telling that to the 3 different weather radios I have with a weak, staticy signal.

[Tstormwatcher]

The same can be said for any major city.

[senorpepr]

I'm not advocating a siren network as THE be-all solution, but it should be a part of the warning network.

I agree that they should be part of the network, but they work best in public areas such as parks and downtown regions. Most of the residential areas are poorly served by sirens.

Nobody should depend on a single means of warning for protection, but it's good to have them.

Nobody should speed while driving, but people do. ...and people depend on sirens as their only method of protection.

I know the sirens in the DFW area are pretty modern with voice/warning information actually read over the system, and cities such as Arlington have been in the news for spending money to upgrade their systems and provide better coverage.

Unfortunately, the modern systems that play the voice are much worse than the standard siren. This goes back to the audibility. As I mentioned before, a regular siren is very difficult to hear when you add the rainshowers, thunder, wind, hail, and every other noise imaginable. A voice system doesn't project as much as a regular siren. The "siren" I live by (a 1/4mi away) is one of those voice sirens. I can't hear it inside on a calm, sunny day. Add in the effects of a thunderstorm... you might as well spend the money on something else.

I can also tell you that a lot of people in this area are from Dallas. Until today, I had no idea we didn't have sirens. This is the first place I've lived where we didn't have them. NOT hearing them would provide a false sense of security.

You mean you never hear the daily noon siren? See, people in a good chunk of tornado alley have that noon siren. They actually can hear that on a normal day. Then, they figure, "I can hear the noon siren... I'm good to go," but they're out of luck when you add in the noise of a thunderstorm.

Furthermore, NOAA radio coverage in the 'burbs here is spotty at best. The transmitter for my area is in downtown Houston, some 30 miles away. Yes, according to the maps we're covered, but try telling that to the 3 different weather radios I have with a weak, staticy signal.

That is odd. In all the locations I've live in within the US, I've always been at least 30 miles from a transmitter. Recently, I have lived as far away as 50 miles from a transmitter. Not once have I ever had a problem. What sort of radios have you tried and where they close to some other electrical device? It's a great shame that you don't have full signal being that close to the transmitter.

[jasons2k]

Sirens in most places I have lived - even in Alabama - only had the test at noon on the first Wednesday of the month, not daily.

I have a couple of different weather radio models. I can get a signal outside in my back yard and in the garage, but hardly at all in the house. Coverage was great in Dallas but the Houston transmitter has always had very spotty coverage.

Look, all I'm saying is that the sirens probably do more harm than good to have them. They do serve a purpose, otherwise they wouldn't be so prevalent in tornado alley, and I'm pretty baffled this is the only major city in TX (besides Beaumont) I know of without them.

[senorpepr]

jschlitz,

Please don't think that my comments are meant to be rude to you or anything like that. I'm glad you made this post and brought awareness to this.

I'm not trying to argue with you, but argue with the sirens. They serve there purpose, but unfortunately too much weight is put on them. That's my point, and I speak it from experience. I'm just saying that not enough push is on weather radios.

[Orlando_wx]

I kinda wish we could take this thread to the mayors here in central florida because after this outbreak of tornado's here they are arguing about should we put sirens in or not and who is going to pay the bill.
Also arguing that radio's are not working solutions so who knows.
John

[jasons2k]

Hey Senor, no worries my friend.

And I think Orlando_wx makes some good points as well. Tornado preparedness is a huge challenge for EOM, especially outside of "tornado alley".

I agree, radios should be used more but unfortunately most people just won't buy one - heck, most people probably don't even have a basic first aid kit. We can offer any number of solutions - sirens, radios, even the new seismic Tornado alarms they are developing - but sadly a good chunk of the population just won't care until the day they get struck - and then will wonder why the "government" didn't save them. Without getting political, it's just the increasingly sad state of America forgetting what the term "personal responsibilty" means.

[brunota2003]

Interesting debate... Did you get another antenna for your wx radio? They have one you can mount on the side of your house for cases where you cant pick up a signal. IMHO, everyone should have a NOAA Wx Radio, they should be pushed as much as fire alarms are...That gives me an idea...

[Aslkahuna]

As an aside, in the paper they mention the 1906 Earthquake as having a death toll of 700-modern day estimates are that it was actually 3-5000 with most of the deaths in SFO-that's important for comparison purposes.

Steve

[JonathanBelles]

We NEED sirens here. With all of the hurricanes and tornadoes here it is badly needed. With all of the elderly people around here it would be apprieciated by many. The police station down the street tries its best but that only covers 2-3 square miles.

[jeff]

The paper that started all this is in this month's BAM. As far as sirens go for metro Houston...I think they are not needed. It is unusual for large intense torndoes in this part of TX...with the last F4 being in 1992. Fact is that we should be much more concerned with a major hurricane that a Moore-Bridgecreek style tornado. Are typical tornado outbreaks are the short lived weak tornadoes in which sirens would be used often and the damage (fence blown down or roof torn off) limited to a block radius. There would be a significant amount of "overwarning" and eventually residents would stop listening if they could hear the sirens in the first place.

[jasons2k]

Coincidentally, I emailed my aunt about the weather in Birmingham today, where my Grandfather lives. I think her reply is pretty telling in how people who live in areas with sirens actually do rely on them for warning:

Strom, Susan
To: Jason Schlitz (jasonschlitz@msn.com)

Subject: RE: Weather

well, at least there are the loud siren warnings in bham.

--------------------------------------------------------------------------------
From: Jason Schlitz [mailto:jasonschlitz@msn.com]
Sent: Thursday, March 01, 2007 10:37 AM
To: Strom, Susan
Subject: Weather


I'll be keeping an eye on this today:

http://www.spc.noaa.gov/products/md/md0234.html

[jasons2k]

Here is an interesting article in today's Tampa Tribune about sirens, etc.:

A State Tornado Warning System Can't Depend On One Solution
Published: Mar 10, 2007
Tampa Tribune

Recent deadly tornadoes in Florida and across the Southeast have prompted local and state governments to consider better tornado warning systems. The temptation is for officials to look for one perfect system - but no such thing exists.

Officials need to create layers of security with multiple opportunities to alert residents. This should have been learned from the pre-dawn twisters which claimed 20 lives in Central Florida last month.

Sirens are part of the solution, and it's good to see that some communities, like Oviedo, northeast of Orlando, recently voted to install a siren system. The town's cost will be $150,000, a relatively modest amount for the capacity to warn large numbers of people at once. The Federal Emergency Management Agency estimates there needs to be one siren for every 3.14 square miles, so in some rural areas sirens won't be practical.

Weather radios, particularly the new ones that can send out alerts to specific areas, also are a good option. They cost at least $40 each so if government wants to rely on the radios, officials will need to make sure the poor can acquire them.

The radios are sold tax-free during the annual hurricane preparedness tax holiday, but perhaps lawmakers should consider a similar tax break leading into the Florida tornado season, which typically lasts from February to April.

Another intriguing technology is weather alerts that can be sent through cell phones. But this would only help people who have the phones and keep them charged and turned on. Reverse 911could have a role too - even though some emergency officials say it takes too long for those systems to send out alerts and there are many people who don't have home telephones anymore, only cell phones.

For every technology that exists, there's a reason why it won't work for some people. And that's why the best weather warning plan involves all these available options.

Think of building security against violent weather in the same way you build personal security. You can use more than one security measure - a lock, an alarm, a dog - to keep your house safer than relying on a single safeguard. The same should be true for public safety.

Since most Florida homes don't have basements, people should have already identified the safest area in their home to take cover - usually an interior hallway, closet or bathroom without windows - so when a warning sounds, they can take cover.

Individuals are ultimately responsible for protecting themselves. It's just like a hurricane evacuation - a warning is just a warning; it's up to you to act to protect yourself and your family.

No one warning system will reach all people all the time. What's important is that state and local governments commit to a comprehensive strategy that will give the most people possible a better chance of surviving these ferocious storms.