James Spann speaks to the NWS and the media concerning tornado warnings and other...

[Greg Stumpf]

A simple work around is to allow a user to manually enter his or her latitude and longitude. Then you still get all the benefits without needing to communicate with a satellite.

Except that the polygon lat/lon coordinates are not broadcast in the SAME code.

The real solution is not over-the-air radio. It is digital info encoded in wireless internet signals, a la GPS-enabled mobile devices that double as phones. Many many more people already have them.

 

[Patrick Marsh]

Except that the polygon lat/lon coordinates are not broadcast in the SAME code.

The real solution is not over-the-air radio. It is digital info encoded in wireless internet signals, a la GPS-enabled mobile devices that double as phones. Many many more people already have them.

Correct. I was operating under the paradigm of that they would be if radios could receive them. I didn't mean to imply that it would work as the system stands now.

 

[Matt Tottle]

A simple work around is to allow a user to manually enter his or her latitude and longitude. Then you still get all the benefits without needing to communicate with a satellite.

...Or they could just start using the system that is already in place and compatible with every SAME weather radio manufactured for the last 15 years or so.. All the benefits without having to make people go out and buy a new radio..

 

[Rob Wadsworth]

I can see how the NWS did their job. The warnings were out there. Sirens blaring and TV warnings working. Any radio station that didn't get on the EAS system was at fault; that is true. But what can be done when a tornado as wide and as powerful as this runs over a city that is in its way? A matador can sidestep a raging bull. But unless a major city can suddenly grow legs and get out of the way - then it will be destroyed. There is nothing you can do despite the very best efforts made. If it was just an EF-1 tornado; we probably wouldn't be having this discussion.

Many of those that sought their 'inner room' were also killed. The extreme wind speed and the massive amounts of debris being picked up and hurled and then re-hurled simply ground up everything in its path. A few did escape as we know. Are we kidding ourselves in thinking that more could have been done beforehand to prevent those deaths?

I think that examining all of this after the fact is a kind of catharsis. An extension of the grieving process, The need to assign blame. I hope that in the final analysis that we resolve Joplin's fate by saying that everything that could have been done was done. This is so. We see the citizens as Joplin as being no different than you or I. We sense common connections, and we feel their pain. It would be just a little heartless if we didn't.

It was ultimately the individual human element that was either uninformed (because of what they were doing at the time), misinformed, willfulness, indifference (the woman in the WallMart parking lot that was inconvenienced by the sirens), or those who took precautions and were killed on its path. It was Sunday; people were at home with family and friends. Just like everybody else across the US at that day and time.

There are so many cities and towns on the Plains; each and every one of them is a potential target and tragedy just waiting to happen. Hallam, Greensberg, and Parkersville - to name a few of the ones over recent years smashed and torn. I think the US has been relatively blessed not having far more tragedies than we had so far. It really could be a whole lot worse than we have seen to date. We all know that it isn't a question of 'if; but 'when'. This year has been the wake-up call that we have already been given reprieves from tragedy. WE all wonder when Chicago is overrun by a number of EF-5's. Or Oklahoma City, or ______. Of course we don't want it to happen. But over a long enough period of time, it is an eventuality that cannot be ignored or dismissed as fear mongering.

There was and is no 'magic bullet' to fix any situation like this. No lack of advanced warning was present. Certainly, not everybody is constantly plugged into the media 24/7. All that can be gathered - IMO - is those that live on the Plains must be constantly reminded of its dangers that can happen at any time. Whatever lessons were learned, is that the tendency to let our guard down is too easy to happen when lulled by a prolonged period of safety. More than anything else, this seems to be true of Joplin.

I think the emergency volunteers did an extraordinary job under the circumstances. Their minds are without a doubt having flashbacks still, and probably will for years to come. If anyone should be listened to about tornado safety; I think they are the real consultants to be considered.

 

[Jesse Risley]

As I say in the interview, it is time to get back to the sirens meaning take cover.

I think this is probably only part of the overall problem with siren apathy. Most people living in areas prone to SVR weather may hear the sirens dozens of times in a decade or two. Probability states that most locations won't take a direct hit by a tornado, as they are relatively rare (statistically speaking) from the standpoint of any tract of land taking a direct hit. Therefore, when those sirens have activated 10-20 times in a decade or two, without any consequence(s) in their immediate hamlet/community/neighborhood, people assume that it was a false alarm, even though according to standard protocol each warning was justified by at least Doppler indicated rotation within a SVR thunderstorm that could very well have produced a TOR with less than a moments notice; therefore, persons in the path just got lucky in all those assumedly "false alarms."

Getting people to understand that tornado warnings without touchdowns in your immediate vicinity aren't necessarily false alarms is one of the most frustrating aspects of discussing SVR weather preparedness with interested parties. This is probably more of a social scientific aspect of research than not, but it's almost as if people expect to know exactly whether or not a tornado is on the ground headed for them directly, perhaps not realizing that we don't yet have the meteorological ability to discern whether or not a SVR storm will produce a tornado if a threshold signature is indicated on radar and, if it does, where, when and how it will strike a given area.

 

[hazelmaryjackson]

I have been following this thread with interest. I live in the UK but am in the US at present, chasing. (Had a good week last week thanks). I am always struck when I come to the US by how vulnerable the houses are in their construction methods to major storm damage. The response seems to be that the chance of being hit by a tornado is so small that it is not worth making them tornado proof outside of Kansas.

Also the houses are cheap to build and to rebuild. So the answer would seem to be to build-in storm cellars or reinforced safe rooms for shelter? Yet a poster above says many people were killed in Joplin in safe rooms. Were these custom built rooms or just internal rooms designated as "safer"?

Then there is the issue of public shelters. A local resident had a letter published in the Joplin press not long before the tornado, suggesting the construction of public shelters. The response from other locals was hostile, saying anyone who wanted a shelter should build their own. There also seems to be a lot of disinformation around about how expensive they are.

Finally, I think the St John's hospital should have invoked their emergency procedures earlier. There may be reasons why private individuals do not heed warnings, but surely not a hospital?

 

[Rob Wadsworth]

hazelmaryjackson:

It is nearly impossible to make homes tornado proof. As mentioned, it is not even the fault of the home design or materials itself. It has much to do with the debris smashing into everything. A house is pulled off of its foundation and is hurled at a nearby house not even in the path of the tornado. Even the smallest objects hurled at these wind speeds can maim and kill - and often does. A harmless pile of road gravel has now become multiple shotgun blasts.

We would all be living like prairie dogs if we allowed the threat of the tornado to dominate us. Burrowed under the ground if we were to overcome the weather found on the Plains. Can you imagine every home across the entire half of the US - East of the Rocky Mountains - with only a door above the surface? An underground garage to store vehicles? Could you live like that? Would you live like that?

Is it optimism that keeps us rebuilding? Lighting only strikes once in the same place is a myth and and has even proven time and again to be false. Perhaps it is optimism. Perhaps it is courage. Perhaps it is foolishness. Perhaps it is the willingness to return to our state of affairs that existed before the storm. Perhaps it is all of the above. Would you rebuild Westminster if it were destroyed by a large tornado?

I am in NW Iowa presently, almost finished rebuilding the family home that was originally built in 1880 by my Great Granddad James. I did make sure that there is a tornado safe room in the basement with a steel door on it for such an eventuality. It is the best that I can do for the new renter. There was a terrible tornado that passed by our house on July 6, 1893. It did take the barn, killed a farm hand, and nearly killed my Great Granddad. But we have been farming it ever since.
http://iagenweb.org/calhoun/story.html
(read down to the heading that says "A Girl Terribly Mangled")

There are over ten times the amount of people living in the US since the 1880's. More homes, businesses, people that potentially are in harm's way. Therefore, the chance that more can be killed has also increased in proportion. I would have to say - IMO - that we don't give up. We don't allow tragedy to dominate us. You can decide if it is ultimate foolishness or the willingness to put on our best face and carry on.

In truth, it is impossible to fault the system that exists. The infrastructure and government are not to blame either. One can ultimately do so much before the weather makes fools of us all once again. And it will . . .

 

[Greg Higgins]

I am going to disagree with the statement "it is not the fault of the home design or materials itself". It is very MUCH the fault of these 2 factors! Now, I realize that there is not much the will stand up to an EF5 but the fact is that ALL building construction has gotten skimpier over the years. A 2x4 is now 1 3/8" x 3 1/4". Sheet rock has replaced other types of interiors (for the fire protection rating, which I am thankful for!) but it provides NO protection for anything else. If you look at the photo's from Joplin you will notice that there are very few brick veneer or stone houses but those that were there faired better than the all wood construction. Of the wood construction, those that had ALL wood, including shiplap interior walls and ceilings faired better than those with sheetrock interiors. The words "faired better" meaning that there was more of the structure still visible. It is going to be interesting to read the report from the NWS and foresenic engineers when it becomes available.

 

[Brett Nickeson]

I am going to disagree with the statement "it is not the fault of the home design or materials itself". It is very MUCH the fault of these 2 factors! Now, I realize that there is not much the will stand up to an EF5 but the fact is that ALL building construction has gotten skimpier over the years. A 2x4 is now 1 3/8" x 3 1/4". Sheet rock has replaced other types of interiors (for the fire protection rating, which I am thankful for!) but it provides NO protection for anything else. If you look at the photo's from Joplin you will notice that there are very few brick veneer or stone houses but those that were there faired better than the all wood construction. Of the wood construction, those that had ALL wood, including shiplap interior walls and ceilings faired better than those with sheetrock interiors. The words "faired better" meaning that there was more of the structure still visible. It is going to be interesting to read the report from the NWS and foresenic engineers when it becomes available.

I'm going to disagree with your disagreement. I am a structural engineer so I can speak relatively intelligently about most of your points. First off, a 2x4 is 1.5"x3.5", and has been that way since the early 1960's. Brick veneer will help stop debris, but structurally it is no stronger than the wall supporting it...meaning it has no out of plane strength. If the wind pressure is enough to blow down the stud wall, it will blow down the stud wall with brick on the face as well. It's also a common misconception that just because a house is built of stone, masonry, or multi-wythe brick that it is stronger than a wood framed house. A 6" masonry wall has less bending strength than a 2x6 exterior wall. Yes, it stops debris better, but that isn't going to do you much good when the wall has collapsed on top of you. Also, believe it or not, construction methods today are much better than what they were in the past, mainly because there was no governing code or code of standard practice for residential construction. I have done many residential inspections and I can confidently say that wooden homes today are constructed better and with tighter tolerances than homes built in, say, the early '40's. They still aren't great, but they are better.

Also, drywall, shiplap interiors, lath and plaster, or any other type of interior finish serves absolutely no structural purpose whatsoever (other than lateral bracing of studs), and in any tornado of any reasonable strength will make no difference in the structural performance of your home. None. I can take a piece of debris and drive it through drywall at 90 mph as easily as I can on any other interior finish.

The simple fact is this: no reasonably built home is going to withstand the impact of an EF5 tornado. Even an EF4 or EF3 most likely. Many deaths this year can be attributed to the simple fact that the strongest ones hit populated areas, and that there was a lack of basements, which are often times impossible to build in many locations in tornado alley. High water tables (southeast), shallow bedrock (areas of Missouri and Arkansas), and expansive clay soils (Texas) contribute to this. To be honest, I am actually amazed watching the videos of those tornadoes that more people weren't killed.

Can homes be constructed better? Sure they can. Hell, sometimes going through the International Residential Code I'm shocked at what is allowed structurally. But designing a home to properly withstand 130 mph winds is insanely expensive. Trust me on that, I've done commercial designs in hurricane areas in Florida. Besides, if you get any debris flying into the house the only thing that will save you is a solidly grouted masonry wall or a home with concrete exterior walls. It's just not practical, and to say that going back to shiplap siding and brick veneer will protect us better is a fallacy.

 

[Michael.Brewer]

I'm going to disagree with your disagreement. I am a structural engineer so I can speak relatively intelligently about most of your points. First off, a 2x4 is 1.5"x3.5", and has been that way since the early 1960's. Brick veneer will help stop debris, but structurally it is no stronger than the wall supporting it...meaning it has no out of plane strength. If the wind pressure is enough to blow down the stud wall, it will blow down the stud wall with brick on the face as well. It's also a common misconception that just because a house is built of stone, masonry, or multi-wythe brick that it is stronger than a wood framed house. A 6" masonry wall has less bending strength than a 2x6 exterior wall. Yes, it stops debris better, but that isn't going to do you much good when the wall has collapsed on top of you. Also, believe it or not, construction methods today are much better than what they were in the past, mainly because there was no governing code or code of standard practice for residential construction. I have done many residential inspections and I can confidently say that wooden homes today are constructed better and with tighter tolerances than homes built in, say, the early '40's. They still aren't great, but they are better.

Excellent read.

A question I have is do you think that eliminating eaves, gable roofs, and certain porch overhangs would help keep a roof in place and give a house a better chance of surviving? I would think decreasing the surface area that the horizontal and vertical winds could "catch" would help significantly. But I know that not many people would want to live in some type of round house or buy one for that matter, so I'm not sure that looking at overall house design is feasible.

I just think that keeping the roof in place is a high priority in preserving the structure. Any thoughts on how to do that in both design and building practice?

 

[Matt Tottle]

To a small degree maybe, but in the big picture, no. Reason being the amount of vent area required in an attic by code. These vents allow wind inside, which makes it more vulnerable. You can't eliminate venting either because otherwise you create mold issues in the house.

There isn't a whole lot you can do to reinforce the house itself without incurring great expense, but one can install a prefabricated safe room for a fraction of the price of whole-house fortification. For even less cost one can fortify a basement room with I-beams, plate steel, and Kevlar to provide protection even in the event that the ground floor is peeled up or projectile debris is hurled through the floor.

 

[Greg Higgins]

Glad to have a structural engineers input! If I might suggest that you go to your local Lowe's or Home Depot, etc. and actually measure what they sell as a 2x4 you may be surprised at what you find. Also from ASTM fire studies, the nominal dimenison of structural wood products is decreasing and is allowed based on engineering studies regarding how much of a load it is carrying. Let me also clarify, I am NOT saying that a brick veneer or stone / masonary veneer provides structural strength; it is only a decorative cover. What it does do, and is backed up by some of the research from Texas Tech, is provide protection from penetration of the debris. The same goes for interior finishes. It is just that, a finish, it provides no structural support. However, you can have debris ripping through sheetrock at lower wind speeds than other finishes (i.e., shiplap, brick, etc.).

Construction methods ON PAPER may be better but fact after fact has shown that the actual implementation is FAR worse! The quality of the work by untrained / poorly trained / low paid workers is atrocious and there aren't enough inspectors to catch everything. It amazes me that contractors will stoop to this level just to make a few more dollars or flat out just don't care. When I was contemplating building a new home I included hurricane clips in the specs. It was amazing how uninformed some of the contractors were. One said that there was no such thing and another added $10,000 to the cost to install them!

One thing that has stuck with me over the years is a comment from a storm damage assessment guy that was saying basically that if "we" (man) could limit the amount of debris through better construction, then there wouldn't be as much overall damage caused by debris. Wind damage is another topic!

Thanks for commenting! I see that you recently joined and hope that you will continue to add your knowledge to these discussions!

 

[Greg Higgins]

There isn't a whole lot you can do to reinforce the house itself without incurring great expense

Don't forget about hurricane clips as discussed in the FEMA document after the May 1999 Oklahoma storms. I priced them several years ago and for an ~3500' foot house, materials would run about $2000-2500.

 

[Brett Nickeson]

Excellent read.

A question I have is do you think that eliminating eaves, gable roofs, and certain porch overhangs would help keep a roof in place and give a house a better chance of surviving? I would think decreasing the surface area that the horizontal and vertical winds could "catch" would help significantly. But I know that not many people would want to live in some type of round house or buy one for that matter, so I'm not sure that looking at overall house design is feasible.

I just think that keeping the roof in place is a high priority in preserving the structure. Any thoughts on how to do that in both design and building practice?

To a small degree maybe, but in the big picture, no. Reason being the amount of vent area required in an attic by code. These vents allow wind inside, which makes it more vulnerable. You can't eliminate venting either because otherwise you create mold issues in the house.

There isn't a whole lot you can do to reinforce the house itself without incurring great expense, but one can install a prefabricated safe room for a fraction of the price of whole-house fortification. For even less cost one can fortify a basement room with I-beams, plate steel, and Kevlar to provide protection even in the event that the ground floor is peeled up or projectile debris is hurled through the floor.

In short, what Matt said is pretty much accurate. Due to venting considerations eaves and overhangs are fairly necessary. The one option around this is a simple framed gable roof on every home, which would allow venting on the vertical roof sides.

But to more accurately answer your questions Michael, yes, eliminating overhangs would definitely help. Wind uplift coefficients are roughly two to two-and-a-half times higher for overhangs than they are for the remainder of the roof, and that is only taking into account horizontal winds. Strong updraft winds in a tornado vortex would amplify this effect many times over.

There are many engineering solutions available to keep roofs attached to homes and to resist strong uplift forces in general. As Greg mentioned, hurricane straps are a good solution, but they are not a complete solution. You have to be able to provide a complete and sound structural load path to the foundation. You can tie the roof trusses or joists to the top plates of the walls, but then you have to strap the studs to the top plate since nails have very little capacity in withdrawl. Then you have to provide the same straps at the bottom of the wall to tie the studs to the sill plate, and finally you have to adequately anchor the sill plate to a foundation large enough to completely hold down the house. By the time you get done with all of this, you've spent probably 10-15% of your homes original worth, and even then it is only going to withstand a small tornado if you're lucky.

Along the hurricane coasts, as you might imagine, these straps and clips are required even for basic residential structures. They are not in the midwest as our design wind speed is only 90 mph, as it is through most of the country. Governing codes recognize that you cannot economically build a home to resist the ridiculous wind forces associated with strong tornadoes. I can confidently say that I could design a conventional wood-framed home to withstand 150-160 mph straight-line winds, but I couldn't say that I could design the same home for a tornado with 150-160 mph winds. They are just a different animal.

 

[Brett Nickeson]

Glad to have a structural engineers input! If I might suggest that you go to your local Lowe's or Home Depot, etc. and actually measure what they sell as a 2x4 you may be surprised at what you find. Also from ASTM fire studies, the nominal dimenison of structural wood products is decreasing and is allowed based on engineering studies regarding how much of a load it is carrying. Let me also clarify, I am NOT saying that a brick veneer or stone / masonary veneer provides structural strength; it is only a decorative cover. What it does do, and is backed up by some of the research from Texas Tech, is provide protection from penetration of the debris. The same goes for interior finishes. It is just that, a finish, it provides no structural support. However, you can have debris ripping through sheetrock at lower wind speeds than other finishes (i.e., shiplap, brick, etc.).

Construction methods ON PAPER may be better but fact after fact has shown that the actual implementation is FAR worse! The quality of the work by untrained / poorly trained / low paid workers is atrocious and there aren't enough inspectors to catch everything. It amazes me that contractors will stoop to this level just to make a few more dollars or flat out just don't care. When I was contemplating building a new home I included hurricane clips in the specs. It was amazing how uninformed some of the contractors were. One said that there was no such thing and another added $10,000 to the cost to install them!

One thing that has stuck with me over the years is a comment from a storm damage assessment guy that was saying basically that if "we" (man) could limit the amount of debris through better construction, then there wouldn't be as much overall damage caused by debris. Wind damage is another topic!

Thanks for commenting! I see that you recently joined and hope that you will continue to add your knowledge to these discussions!

Thanks, always happy to nerd out somewhere besides work.

But again I'll say, the milled thickness of sawn lumber has not changed in the last 50 years. At all. Even though the governing lumber spec (U.S. Department of Commerce Voluntary Product Standard PS 20) is "voluntary" there are no mills or lumber manufacturers that deviate from this standard, as they are the ones that requested that these dimensions be the standard. I'd be willing to bet a bucket of beer that the lumber you are measuring has a very low moisture content and has already undergone it's shrinkage. All wood does this unless it is kept moist (which, by the spec, is not allowed since any wood qualifying as dimensional lumber must be kept under 19% moisture content). If you go into houses built over 10 years ago or so, you'll find that nearly all of the joists, studs, and framing are smaller than what they started out as. For example, I was just in a 40 year old home a few months ago retrofitting a kitchen to support a new concrete island (the size of three compact cars, but I digress). The joists supporting the kitchen floor were 8 15/16" deep, instead of the 9 1/4" deep that they started out as. I would also love to see the ASTM fire standard you refer to, especially "the nominal dimenison of structural wood products is decreasing and is allowed based on engineering studies regarding how much of a load it is carrying" because that is a completely false statement on both aspects. Actual dimensions (I believe you meant actual instead of nominal) are not and have not changed in a very long time, and are most certainly not allowed to change on a case-by-case basis based on applied loads.

I hope I'm not coming off as hostile, but some of the things you've been led to believe are simply not true. This is one of the few things I can talk intelligently about on here!

I do agree with you about the debris damage in principle, but in reality it would be next to impossible to implement. After all, if you have a Volvo thrown through your bedroom wall it doesn't matter much if you had veneer or shiplap siding covering your walls.