Saturday, April 21, 2012

What does "Storm Ready" really mean?

Many of my readers know the National Weather Service has a program called "StormReady" that gives communities "StormReady" status when they meet certain criteria.  You can read the criteria on their website.  Some recent experiences here in my community - Norman, OK - have given me reason to doubt Norman's actually readiness for storms, in spite of their having been granted this "distinguished" status.

I wrote an extended essay after a tornado developed near my home late at night in 2009.  The local sirens weren't sounded until well after the tornado began, apparently because no one was in the Emergency Operations Center (EOC) to push the button.  On 13 April 2012, a tornado developed just west of Norman and moved across the heart of the city, wrapped in rain.  It turned out to be a weak tornado (EF-1), fortunately.  It dissipated not far from my home.  The sirens again were not sounded until the tornado was well into the city - apparently again because no one was staffing the EOC.  Just how "storm ready" can Norman actually be if this is their track record in threatening situations?  Why was there no one already at the EOC in these situations?  Having an EOC is not very meaningful if there's no one there to operate the facility.

Sirens are not the best means of disseminating tornado warnings, but Norman recently spent a fair sum to install new sirens.  Was this the best possible way to use that money?  I think not.  Apparently, from what I heard, the mayor made that decision on her own, basically, for reasons unknown to me.  I'd like to see the general public wean themselves of their dependence on sirens as their sole means to alert them of approaching hazardous weather.  Yes, sirens might still have a useful function, but people shouldn't be accustomed to depending on them alone to obtain information about the weather.  Whatever I might think about the efficacy of sirens for tornado warnings, however, these two recent incidents seem to suggest that Norman is not so ready for storms as their resume might suggest.

What does "storm ready" really mean?  As I see it, the NWS criteria don't go nearly far enough to establish a meaningful preparedness level for communities to meet.  To be truly ready, communities need to do much more!  For example, who has reviewed and approved the tornado plans in place in the local public schools?  Have those plans been evaluated by someone independent of the school who actually has the qualifications to know what's needed?  Dr. Matt Biddle and I have done some informal snooping around in schools over the years and found several disturbing things:
  1. Many schools don't have a functioning weather radio
  2. The designated shelters in many of the schools I've investigated have serious problems that would endanger anyone sheltering there
  3. Schools often have suitable shelter spaces that are unnecessarily unavailable for use - e.g., interior rooms filled with stored items
  4. The structural integrity of school buildings is not always known, so any structural defects that could affect safety need to be identified by someone competent and those flaws fixed
  5. Some of the tornado plans I've seen contain fundamental flaws that could put children and staff at risk
A similar evaluation of all the other places in a community where people gather - businesses, malls, recreational facilities, universities, private schools, hospitals, nursing homes, churches, and so on - should be undertaken.  Most of our concerns with tornadoes are focused on residences, and deservedly so, but they're not the only locations where people are at risk in a tornado.  Residential building codes should be in place that mandate enhanced structural integrity.  Families and businesses need to be encouraged to develop tornado hazard plans and to practice them at least once a year.  Public information campaigns to make the community aware of their responsibilities and resources should be routine.

In my experiences here in Norman, the politicians seemed distinctly uninterested in taking full advantage of the numerous subject matter experts in the university and the Norman Weather Center.  Similarly, it seems many of those experts have little interest in contributing to the improvement of the community's preparations for storm hazards.  That this is the case here in Norman seems incredible to me.  How can we presume to lecture to others about what to do to prepare for storms, when our own community is not a shining example of what can and should be done?  Is Norman truly storm ready?  I don't think so!  That should be an embarrassment to everyone.

Friday, April 20, 2012

The false dichotomy: Tornadoes and home construction

The widespread prevalence of mythology seems to characterize the whole subject of tornadoes and their interaction with humans.  For example, I recently wrote a blog about the myth of water tables preventing the construction of basements.  Someone recently passed on to me a "Disaster Safety Review" put out by the Insurance Institute for Business and Home Safety, that contains some fascinating material, that I'll address shortly.

However, the main issue compelling me to write this blog is a false dichotomy:  the builders and their lobbyists say that it's possible to build a tornado-proof home, but no one could afford it or even want it.  This argument presumes that the only two options available to a prospective homeowner are either (a) a tornado-proof bunker, or (b) the standard, flimsy frame home built in the USA.  That this is a false dichotomy should be evident to anyone who knows anything about construction.  It's quite possible to construct homes that would resist damage from tornadoes - that is, to some standard somewhere intermediate between (a) and (b).

As should be well-known, the hurricane-prone regions along the Gulf of Mexico and Atlantic coasts have building codes that mandate homes be built with more structural integrity than is required for homes in the rest of the nation.  Essentially, outside of the coastal zones, the standard is that the home be constructed to resist structural damage in winds up to 90 mph - this is option (b), above.  In the coastal zones, the standard is up to 125 mph!  Apparently the builders are quite capable of building homes to that higher standard (assuming it's actually enforced).  Note that this higher standard does not make homes either hurricane-proof, or tornado-proof!  Their enhanced structural integrity makes them hurricane/tornado-resistant, however. Such homes can be built and apparently they're affordable!

In even a violent tornado (EF4-5), the violent damage comprises only a small percentage of the damage path.  Therefore, by far the majority of the damage path area experiences winds of EF-3 or less (currently, the bounds of EF-3 are nominally 136-165 mph).  If we had all new homes built in the USA held to the higher standard applied in the hurricane-prone regions of the US, we eventually would have far less structural damage to homes, even in violent tornadoes!  In EF-2 and weaker tornadoes, structural damage would be nearly eliminated.  Reduced structural damage would provide reduced debris loads in tornadoes, and it's well known that debris within tornadic winds makes those winds considerably more destructive!

Of course, a lot of "legacy" homes will remain for a long time that were built to the lower standard (b).  Their structural damage would still contribute debris that could affect the damage even in well-constructed homes.  Airborne debris from your neighbor's flimsy home could "reach out" and harm your home, even if your home is well constructed.  I've seen examples of this in my damage surveys - it's not enough just to have your home well-constructed!  Whole neighborhoods and, eventually, whole communities need to be well-constructed to provide the optimum safety from unnecessary damage.  This problem can't be corrected overnight, obviously, but if we do nothing to enhance building codes within the tornado-prone areas of the USA (essentially everywhere east of the Continental Divide), then we'll be plagued indefinitely with what amounts to unnecessary damage from tornadoes.

I note that in the safety review mentioned above, the states of TX, MS, and AL are rated quite low in terms of building code and enforcement.  If one were to search for reasons why tornado outbreaks in "Dixie Alley" produce so many fatalities, this might be a good place to start!