Sunday, April 29, 2012

A magic bullet for tornado warnings?

After the tragic tornado season of 2011, with nearly 600 fatalities, it's natural for some agonized re-appraisal to go on.  Some blame themselves, some blame others. But the "blame game" is pointless.  How do we explain all those fatalities, despite the fact that the National Weather Service (NWS) and the so-called Integrated Warning System (that includes media broadcasters and emergency managers, as well as storm spotters and NWS forecasters) did a pretty good job with having tornado warnings out for the deadly tornadoes?

Of late, it's become fashionable to discuss the issue of the efficacy of warnings in terms of the need to do social science-oriented research.  In fact, I've just returned from the Weather Ready Nation Workshop in Birmingham, AL where the main goal was to define research objectives for a multidisciplinary approach to the challenge posed by large death tolls in spite of reasonably timely and accurate warnings.  Hopefully, the outcome of this workshop will be a major step forward in getting the needed multidisciplinary research done.

For decades, the NWS has been focused, naturally enough, on the weather!  During most of my career, most forecasters operated under the notion that they have a forecasting task to accomplish that basically ends when they push the "send" button on their computers and their forecast products (including tornado warnings) leave the office (mostly electronically).  They've not considered it their responsibility to understand what happens when it leaves the NWS office - and it shouldn't be their job.  Weather forecasting is tough enough!  My long-time friend and colleague, retired NWS operational forecaster Alan R. Moller made me aware of the inadequacy of this situation:  even a perfect forecast is useless if the forecast information:
  • Fails to reach its intended users
  • Is not understood by the intended users
  • Is not believed by the intended users
  • Is of no value in helping intended users to make critical decisions
For the last year, there's been a lot of angst over the warning process.  What can we do to make them more effective?  What can we do to prevent any of the foregoing stumbling blocks along the path to protecting the lives of those unlucky enough to be in the path of tornadoes?  To a considerable degree, solutions to the problems depend on information about the users we presently don't have, and have only begun to obtain.  Weather forecasters aren't qualified to do the research needed for this - they know meteorology, not social science.  Partnerships between the meteorologists and the social sciences must develop as a result of mutual interest in answering the as-yet unanswered questions about what happens when the forecasters push "send".

I've long been an advocate on behalf of this research and I continue to believe we need those answers before we start meddling with the warning process.  No doubt in reaction to all the angst, the NWS recently initiated a public "experiment" in tiered warningsThis is an ill-advised, ill-designed experiment. It "recycles" some old terminology and represents nothing particularly new. Its experimental design isn't founded on new understanding of how the public receives, understands, and uses warnings to make decisions. Moreover, it shouldn't have been carried out in a "public" mode. The ability to issue skillful tiered warnings should have been tested in a non-public, "testbed" mode before this project was undertaken - the HWT at the Norman Weather Center would have been an ideal venue for a series of internal experiments establishing the extent of forecast skill before going public. And the physical and social scientists should have been given the opportunity to review this experiment and offer recommendations before the ill-advised decision to go ahead with this was ever made.

Having said all this, I now want to throw  some cold water onto the entropy generated by all this anxiety over the warnings.  First, in my opinion, there's no magic bullet that will transform the existing warnings into something where all the challenges described above are overcome.

Is it our goal to turn the public into automatons who shuffle off like zombies to shelter every time we issue a warning?  Personally, I don't think so.  We have no business telling our forecast users what to do.  The meteorologists need to issue their warnings, but the users must make their decisions about what to do with our weather information on the basis of their own complex needs, which vary from one user to the next.  This diverse set of user needs can't be accounted for in NWS warnings and so I'm opposed to such things as call-to-action statements.  If people need to know what to do in specific situations, the time to learn that was before the threat ever materialized, not in the last few minutes before a tornado strikes.

Although the existing warning system is far from perfect, its impact on life-saving over the years has been dramatic.  I have no doubt that thousands of lives have been saved by the existing imperfect warning system.  Before we start tinkering with the warnings, we need to be as certain as possible that any proposed changes won't result in even less effective warnings than they are now!  First of all, do no harm!!

Second, it's obvious to me that mere wording changes aren't likely to have any lasting impact on the warnings.  We have to reconsider the whole process, end-to-end (to use a phrase that once was popular in NWS management circles), and make changes only on the basis of clear and compelling new findings about the warning process.  Wordsmithing is of little or no value.

Third, the existing warnings do their best with respect to the tornadoes that are most likely to take lives:  long-track violent tornadoes.  We're already doing pretty well there and the rest of the tornadoes only account for a small fraction of the fatalities.  When large, violent, long-track tornadoes hit populated areas, people will be killed.  Most of the time, tornadoes miss population concentrations here in the USA.  A comprehensive explanation for the massive death tolls in 2011 has yet to be offered, and likely involves some complex interactions among factors leading to casualties, but it's my belief that the primary "explanation" is that our luck ran out in 2011.  The threat has been there all along, but we were mostly unlucky in 2011, whereas we've mostly been lucky in the preceding decades.  This has been characteristic of tornado fatalities over time - sporadic disasters decades apart, with much lesser events dominating in between.   We need to review and consider who is being killed in deadly tornadoes and the reasons for their deaths.  I don't believe the "answer" to preventing fatalities is longer warning lead times by tornado forecasters.  As noted, we're already doing a pretty good job with most of the really deadly tornadoes, paradoxically.


Teena said...

I agree with your point that we need to understand "how" people died in tornadoes before we start changing warnings. It is quite possible that in some cases (Joplin comes to mind, as well as Moore/OKC a few years ago) fatalities were not a function of inadequate warning, but a function of not being in an adequate shelter. Or a function of choosing not to take shelter. Warnings and information can influence human behavior, but it cannot control it.

(Grew up in Arkansas with many memories of going outside and looking up when sirens went off. Grandparents lost everything in the March 1997 tornado, which taught me the fascinating damage a tornado can do. Now live in Missouri, which has it's own fair share of tornadoes.)

Teena Reasoner said...

I left only my first name in my previous comment before realizing that my last name was required. Sorry! I am Teena Reasoner.

Steve Dieli said...

My wife and I just recently moved our family from southern California to central Oklahoma (Norman) so that I may be able to attend OU's SOM. One major consideration for us while we shopped for a home to buy was whether it had a storm shelter and if it was large enough to accommodate our family of five. This is not, I believe, second nature in our society; that is to seek out residence with adequate infrastructure for short-term, disaster-ready self-sustainment.

I experienced the 1994 Northridge earthquake first hand, living about 7 miles from the epicenter. I was only 16 at the time, but what that earthquake did was instill a very strong sense of the magnitude of destruction this earth was/is capable of doing to our human society. This is desperately lacking today and I think it is because of the desensitization of the populace from the proliferation of disaster type media made available by outlets like YouTube.

My family and I have experienced exactly one tornadic supercell thunderstorm, 13 April 2012. For the sake of disclosure, we lived in Fort Worth for just over one year and while living there experienced a robust derecho event on 1 June 2004. I will admit, I was scared. I did not come to Norman because I love tornadoes, I came here because thunderstorms scare the shit out of me and, as such, I have an unquenchable thirst for knowledge which serves to abate my fears with understanding. So I take warnings very seriously and do not wish for tornadic supercells for anyone. I understand the fascination and I think that it should be encouraged, as this is what has gotten our knowledge where it is today.

In that respect, I believe that further prodding of these storms is absolutely part of the answer to the question everyone of why so many people have perished in the last year due to tornadoes. Socially, it is the responsibility of the media outlets like YouTube to run PSA's before people watch these tornado videos to provide the education necessary for the viewer to make the right decision when it comes to "game time." The Weather Channel is another outlet that, instead of advertising how awesome and heartfelt their coverage of Joplin was, bears responsibility for sharing in the education process (which they use to provide on a regular basis prior to being owned by NBC/GE/Comcast). I'm not looking to blame anyone or anything, I just want to see the people step up that need to step up.

Stephen Dieli

Chuck Doswell said...

Stephen ... I would also like to see the media fulfill their part of the responsibility for educaating the public. That chasing should be encouraged ... well ... I have reservations about that.

Steve Dieli said...

Maybe encourage was a poor choice of wording. My point with it was that even though I myself do not partake in the activity of storm chasing, I can see the benefits to the community when those involved act in a responsible manner.

Eric Weaver said...

Here is a question that would be interesting to know the answer to.

Are the avoidable tornado fatalities (i.e. people who had some sort of access to appropriate shelter but did not go there) the result of:

1. Their duties required them to be on post (such as a policeman) and they could not leave without being derelict in their duties.


2. They made no attempt to pay attention to the weather, and the well-warned-for tornadoes surprised them.


3. They knew all about it, but chose not to take shelter for some reason. (Did they tell other people who survived WHY they made that decision? Playing chicken with a tornado? Suicide by tornado? Just plain stupidity? Enquiring minds want to know!)


4. What seemed like reasonable shelter turned out not to be.


Chuck Doswell said...

Eric ... reasonable questions, the data for which I don't have. Someone has to do the research ...