Thursday, November 11, 2010

Chasing mythology - 1

A persistent myth associated with storm chasing is that by getting measuring systems into tornadoes, this provides data for research that ultimately will lead to saving lives. I see this myth repeated enough in media interviews to become something of a mantra for everyone out there chasing tornadoes, both privately and for actual scientific programs like VORTEX-2. It usually is coupled with the notion that such research will increase tornado warning lead times, and the result will be lives spared.

Putting scientific instruments into tornadoes involves considerable risk - we see this on the TV soap opera "Storm Chasers" on a routine basis. It's not inconceivable that chasers could be seriously injured or killed in such attempts. In fact, the more risks taken, the more likely such casualties become. But what's the potential benefit of learning more about what goes on inside tornadoes? I think obtaining such measurements is an important way to learn more about tornado dynamics. But - I have no reason to believe that an increased knowledge of tornado dynamics will have any impact whatsoever on the issue of providing improved tornado warnings!

As I've written elsewhere, tornado warnings for the types of tornadoes most likely to cause casualties are already pretty good, for the most part. Most tornado fatalities occur in association with tornadoes for which the warnings were out well in advance, rather than with those tornadoes occurring with little or no warning. Casualties from tornadoes for which no warning was given are not unheard of, unfortunately, but only comprise a relatively small minority of tornado casualties. The tornadoes most likely to cause casualties are violent, long-track tornadoes that only occur rarely without being anticipated well in advance!

Moreover, having a lot of knowledge of tornado dynamics does nothing obvious that will improve our ability to anticipate which storms will go on to produce tornadoes. It seems evident to me that studying the effect (the tornado) is not likely to provide much help without knowing a lot more about the cause (the storm that produces the tornado). The single biggest issue confronting those responsible for issuing warnings (i.e., National Weather Service forecasters) is how to recognize in advance:

(1) which storms will go on to become tornadic,
(2) when such storms will begin to produce tornadoes, and
(3) when such storms will stop producing tornadoes,

with high confidence (and accuracy). As of this moment, our attempts to do so in the real world are not always very accurate - we issue far too many false alarms because we generally prefer to warn for a storm that doesn't produce a tornado, rather than to miss putting out a warning for a storm that does become tornadic. No one ever is killed by a non-event.

This uncertainty is not about the tornadoes themselves (and their inner workings) but is all about the storms from which tornadoes are produced. If someone wants to improve tornado warnings, we need to learn precisely why most severe storms don't produce tornadoes, and how to recognize that with some reasonable degree of confidence. It's at least as difficult not to issue a tornado warning (when none is needed), as it is to issue that warning (when it's appropriate to do so).

When people justify the risks they are taking in order to obtain data inside tornadoes, it's basically not true that such research will lead to saving lives in the future. There may be perfectly valid reasons to learn about tornado dynamics, but saving lives simply isn't among them.

24 comments:

bc said...

Chuck,

Two comments...first, we're really not going to see forecasters' confidence in tornado warnings until such time as forecasters are required (or perhaps dragged, kicking and screaming) to express those warnings probabilistically. Until then we'll hear about "possible tornadoes", "tornado might form", etc. As you well are aware, probabilistic warnings will require a culture change, a change that I for one am not optimistic of. We can throw all the realtime data and previous research at the problem to no avail. Changing the warning format is easy. Changing the mindset of the organization is quite another problem.

Second, regarding the "probes" of tornado vorticies: individuals or groups, whether acting in the name of science or business, are flat ass stupid. There is no ROI where there exists a high probability of death. It's still a free country, however, and if folks wish to nominate themselves for the Darwin Awards, I suppose we should allow it. Same goes for those who wish to contribute to those activities via watching reality teevee. Chlorine in the gene pool and all that...

Welcome back!

===== Roger ===== said...

I am so glad you wrote this--not that it will convince the TV "chasers" to quit spouting their breathless but baseless self-justifications that propagate the "help warnings" myth, but simply as a reference for those of us who field questions about it from time to time to set the record straight.

The whole idea that these TV chasers' data "improves warnings" is just plain bogus. This applies in real-time situations also. None of the actual measurement data that are being collected in and near tornadoes is getting to the NWS warning forecaster immediately, if ever. What is being used for real-time warnings instead (besides radar and, in some cases, mesoanalysis)?

1. Visual reports of wall clouds, funnel clouds and tornadoes via SpotterNetwork and ham radio as a part of standard storm-spotting operations that already exist anyway, and
2. Increasingly, live video-streaming of salient storm features from chasers and spotters so equipped.

The self-promotional loudmouths have made it clear that they don't care what you or I think. It's all about ego, greed and attention. It's manifest as fabricated drama, set amidst assorted footage of real storms that may have been shot on other days, all for the sake of ratings.

Some of these "chasers" are being used like cheap whores by the TV producers, either quite willingly, or in ego-blinded ignorance. Either way, what does that say?

I gather from the numeral in the title that you've got other myths to address also. Outstanding! I can guess what some of them are, but instead will eagerly await your follow-up(s).

Chuck Doswell said...

BC,

As you know, I'm a believer in probabilistic severe weather warnings, but that's a bit off-topic here. As things stand currently, tornado warnings are binary (dichotomous) .. either a warning is issued, or it's not.

Granted, it's a free country and people can do as they see fit until such time as laws are passed making it illegal. But I'm disputing the fiction that taking such risks is based on the noble goal of saving lives. Whatever might motivate folks to take such risks, their actions are not going to have any effect on tornado casualties - unless they become tornado victims in the process!

Kenny Blumenfeld said...

I think part of the myth arises from justifying the expenditure to potential funders who are non-experts. If you are going to be disingenuous with them, you probably better keep your message consistently disingenuous when you go public with it!

Like Roger, I am anxious to see the sequel posts. Considering that this season's "Storm Chasers" is subtitled "Why We Chase," there should be no dearth of material!

Chuck Doswell said...

Kenney,

I won't be gathering much material from "Storm Chasers" as I don't plan on watching very much of it!

Chill said...

I like the idea of challenging myths. Not only does pop culture create and perpetuate myths, so do scientists, and they just generate more information that appears believable.

For example, one of the tornado myths, that is fortunately declining in popularity, is the myth that to survive an EF5 tornado, you just need to jump out of your car and dive into a ditch.

This myth is not only highly inaccurate, it is potentially deadly.

I have seen sections of paved highways where a measly EF4 tornado has sheared off the surface of paved road and scored a foot of dirt out of the ground, in a c shape, surrounding the road where the tornado passed over.

The truth is, and all storm chasers know this, if you can, evacuate from the path of a tornado to survive!

Abandoning your car on the road to preemptively dive in a ditch only provides yet one more obstacle for other sane drivers to pass around in an effort to drive to safety.

This unqualified dive in the ditch myth has been parroted by scientists and broadcast by seeming weather experts on news channels for decades.

Now regarding the aforementioned myth, that getting air flow, dewpoint, barometric pressure, temperature, and vector measurements from the core flow region of a tornado will add nothing to the science and understanding of tornado genesis, and to obtain such data will add nothing to public policy activities of increasing tornado warning lead times, is in itself a myth. We do not know if it will help emergency managers with lead times or not.

In all probability it will help with understanding the calculus of core flow strength and oscillation of such force over the path of a tornado, and do little to help with predicting lead times.

Advancing and deploying technology that more accurately determines when, where, and how strong a velocity couplet will occur is much more likely to help weather forecasters determine appropriate lead times.

sknr31 said...

best post i've read in awhile...thanx for doing your Chuck thing!

Chuck Doswell said...

Chill,

You kinda sneaked your own material in here. Actually, abandoning a vehicle isn't always the wrong thing to do. Many times, it is, but not always.

What F4 tornado peeled pavement? Where and what date? What kind of pavement? I know of none that have peeled concrete road. I doubt that even interstate-quality asphalt has ever been peeled.

I want to take this opportunity to make a correction to this blog - I said "it's basically not true that such research will lead to saving lives in the future" to "I know of no obvious path by which such research will lead to saving lives in the future".

Jim LaDue said...

First of all, I agree with the message in your post. Afterall, the evidence continues to mount that we cannot do much more to save lives without a fundamental change to the way to the user response to the current warning paradigm, and a change to our tornado resistance. Not considering that some people cannot be saved, it seems that the biggest improvement in dropping casualties will happen when we find out a way to wake up people in the lower half of the social income class living in mobile homes and then get them to shelter. Perhaps if that shelter has to be their vehicles, then we need to figure out what they can do to become debris resistant. The evidence is there that if they can withstand debris impacts while sheltering in their vehicles then they stand better odds at surviving than staying in their mobile homes.

Of course there are those rare tornadoes that will roll up vehicles into unsurvivable pretzels, even while in a residential setting. For those situations, we need to give them more advance warning so that they can be woken up so they can drive away in the right direction.

So I do see a need for these chasers to drive into tornadoes. But to really save lives, they have to calibrate the observed winds in tornadoes to debris speeds, operational radar observations, and storm environment. Of course, the requirement about documenting debris will require them to intercept debris laden tornadoes. And finally, the producers of the various shows need to fund them to try various techniques to resist debris that can be purchased with the small amount of cash that poor people may be able to spare. If one method fails, then other chasers will have to try.

TIV Chaser said...

Chuck,
Once again you have hit the nail on the head. How does taking measurements do anything for warnings? It's really bad when TV is promoting it just for ratings. Then uneducated folks that know nothing about weather will see it and want to drive into tornadoes too. Case in point, when I was in a young kid when there was a tornado warning you went and took cover. Now when a tornado warning is issued kids are going outside and recording it and putting it on YouTube. The warnings are not taken seriously or the level of caution that they were 10 years ago.
If NWS truely wanted to increase warning times, they would pay attention to live streams. There are 3 major groups that provide reliable video that NWS should watch. But you know those government agencies. Even if forced to they won't do it.
I hate to say it. Somethings will never change.

Chuck Doswell said...

Jim,

If the goal is to save lives, I maintain that for people who find themselves in tornadoes without a proper shelter, there just isn't much we can do, realistically. If we want to save lives, we need to keep people out of tornadoes (which includes being in a proper shelter).

Putting chasers into tornadoes just doesn't make much sense to me if we want to save lives!! Opinions vary, of course.

chill said...

Chuck, sorry for sneeking another comment into your thread. Well, the EF4 was on May 22, 2010 near Bowdle, SD. What I saw after the EF4 passed was that the smooth surface ended (was thinking this was paved, but possibly not) and several feet of sub-pavement gravel was just gone for quite a ways. I found this fascinating. I cannot be sure if the surface ended deliberately and all the gravel was removed below the surface by the EF4, or if the EF4 sheared off the surface and gravel base. This is the second time I have seen such a thing. I guess, in all caution, I can say the gravel was scored from the road bed. Needless to say, no human being would have survived in that area, in a ditch or otherwise, had that EF4 passed overhead.

"A quote from Sam Baricklow about the Jarrel F4-F5 Tornado. Quote
The amount of pavement removed by the tornado was amazing. The Jarrell tornado removed more asphalt pavement than the Dimmit, Texas tornado of June 1995."

Dare I say another myth busted, (regarding diving in a ditch) or does that infring on copyright of Myth Busters, so call it a myth dusted.

I do agree with you on one point, if it comes to a weaker tornado, if you cannot out run it, possibly being below road surface could afford some water soaked, tick and snake infested protection from a tornado.

Your revised wording makes sense to me too.

===== Roger ===== said...

TIV Chaser: Many NWS forecasters actually pay attention to live streams, at least to the extent that approved software and bandwidth allow. It can be a valuable warning and awareness tool. Live streams have become a vital part of the Integrated Warning System in some specific situations.

The fact that there are video streams from those chasers who have the spending money, functional equipment, cell coverage, available bandwidth and technical acumen to set them up, is a positive trend. I have used them at my unnamed workplace to get a good read on storm-scale morphology and structure, which offers valuable environmental clues, and in turn, definitely benefits me as a forecaster. Considering how most of the best tornadic storms in "Chase Alley" tend to happen when I'm on evening shift, this is the only way I get to see them in near real-time anyway! :-) I also have used live streams, both from home and work, to report tornadoes to a few offices whose extremely busy staff wasn't yet aware of them.

That said, I know of at least one office that hasn't installed Silverlight due to "security," so those videos that require that software won't be visible. Some offices also start to lose bandwidth when viewing video streams through a shared, regional Internet choke-point; so the practice has been discouraged in a few places. Yes, they should do those upgrades, but until then...what?

Even discounting the problems on the operational forecast side, video streaming can be done MUCH more efficiently and usefully than at present from the provider's end. Here's how:

* All video streaming output should be consolidated into ONE platform (not three!), for simplicity's sake, with
* No special software, subscriptions or plug-ins needed, and as such,
* Viewable as-is from any of the major browsers (MSIE, Firefox, Chrome, etc.).

Simplicity and ease of use are critically important in warning decision situations, where seconds count. Anyone who has sat on the warning desk knows this. The forecaster shouldn't be expected to juggle multiple windows or browser tabs, nor compound his/her frustration in an already intense situation by hassling with errors such as, "This video requires Special Plugin X. Please install Special Plugin X in order to view this video," or, "Please enter login and password below."

chill said...

You are correct about steel reinforced concrete paved road surface, those are designed to witstand certain levels of earth quakes, no tornado would likely rip up any such highly engineered road surface.

Tim Samaras said...

Chuck:

Great comments, and I 98% agree. I have struggled with this the past two years. This year _______ has us saying our lines as they want, word for word. They know that I really struggle on saying 'saving lives' stuff, and I try my best to avoid such nonsense, and I refuse. And ______ knows this.

My feeling is that whatever measurements I provide to the community only covers the DYNAMICS of tornado cores as they pass overhead or nearby. We try to complete the snapshot by attempted measurements of the rest of the thunderstorm process (mobile mesonet observations of FF, RFD, etc).

The above works for _____ most of time, as I've heard myself quoting similar as above on the show.

My goal is to collect numerous observations to know what--and how powerful the wind can become close to the surface(how thick/thin is the boundary layer?). Certainly, there are lots of folks out there that feel that such measurements are totally worthless, and have the right to disagree.

I've had some limited success in these types of measurements, and my intent is to share these results in conference/refereed publications.

How many 'in-situ' measurements are needed? Probably 50-100 or more to get a good average. Will I have a chance to collect this many? Not in my lifetime-but its a start.

I won't beat around the bush--I love being close to tornadoes (well--as close as my 50+ something age will allow). There is something about watching tornado dynamics up close. Some of you were close to tornadoes in the past--and perhaps understand what I'm talking about.

Its OK to call me 'flat ass stupid'...I have thick skin.

Love the conversation--keep it going!

--A Darwin Nominee

Blufie said...

Great comments and read! I always assumed the insitu measurements for tornados were for the wind load and shear calcs - to help with perhaps building codes or design. I had no illusion that the teevee monkeys had any other purpose than ratings as a means to dollars. That is just how business operates. Create a compelling story and sell it!!

I'm also aware of and admire Tim S's work and am glad he chimed in. I don't watch the soap opera but it follows Mythbusters (which I do enjoy) so I occasionally see the intro and I when I saw Tim's face I couldn't help but feel a bit sad and worry he would have to be selling out. Of course someone has to pay the bills - even for science.

As Chuck stated, today's warnings are pretty good with respect to lead time. Unfortnately it's not always possible to persuade people to be prepared or respond. That is just a human condition, In fact, most of the incidents that i can recall of failures in warnings are attributable to the normal non-perfect nature of things. The most well intentioned and capable forecaster makes a mistake or has too many storms to watch, radar or other support tools fail, networks or power to complete the warning system process are unavailable, etc.. People ignoring the warning is not a failure in the warning process.

Can we improve on this? Yes, but not without significant investment and willingness to change. Unfortunately both of those criteria are hard to come by without "strings attached".

Maybe we can mount a write in campaign to get Mythbusters to debunk myths in the show that follows it! Of course even they have strings as they had to "test" and approve the current crop of vehicles designed to let you survive an act of stupidity.

John Moore said...

Chuck, I agree with the point of your post.

However, I disagree with the idea that warnings are pretty good. Not only do we need (and have) a good rate of detection, but we also need, and do not have, a low false positive rate. I believe the false positive rate is well over 70%, which is enough to discourage too many people from heeding the warnings.

So, we do need to greatly improve warnings, although I agree that tornado intercepts will have not have much to do with that. Rather, I would suspect that a much richer, more dense set of operational sensors is what's needed.

Oh, and I agree with Tim. I also enjoy getting close to tornadoes, although not *that* close! At this point, I've admired all the distant supercell structure I need to.

Scott said...

Thank you Chuck, another very informative and interesting essay.

What tools are needed to be able to determine which t-storms are likely to go tornadic? I understand that there is a former military phased array radar operating in your neck of the woods. Is that type of radar much of an aide in tornado forecasting for your area?

What about the OK Mesonet? Is the spacing of the sites adequate or do you need a lot more sites?

If you had a few billion to put towards improving tornado forecasting, where would you put it?

Thank you for your insight.

Chuck Doswell said...

Tim: I would never call you stupid! Far from it! Thanks for chiming in. I have serious doubts that detailed knowledge of winds near the surface in tornadoes is going to save many lives, though.

John: I believe your numbers are for all tornadoes, not those most likely to cause fatalities. I never said warnings don't need to be improved ... only that those improvements aren't going to save many more lives.

Scott: Lots of questions ... that I will answer only briefly. To date, we don't yet know very much about how to recognize in advance which storms will become tornadic. The phased array no doubt will add an increment to our warning capability, but I doubt that that alone will be associated with a dramatic change in the fatality rate. See my essay on how I think we should invest in tornado fatality rates:

http://www.flame.org/~cdoswell/bonanza.html

Chuck Doswell said...

Scott: Sorry I missed the question regarding the OK-Mesonet. It isn't a system designed to deal with storm-scale processes, so it's inherently of only very limited value in tornado warnings. It can be used to analyze mesoscale processes, but its value even for that is being compromised because surrounding states haven't developed comparable mesonets. The mesonet in west TX is good but that's just a start ...

John Moore said...

"John: I believe your numbers are for all tornadoes, not those most likely to cause fatalities."

Chuck, you are more likely to know the numbers than me. But to the public, if all they know is that most tornado warnings don't pan out for them, does the distinction matter?

Another problem, I suppose, is that for warnings which verify, most times the tornadoes don't affect a significant percentage of those warned. I don't know how this plays into the psychology of warnings.

Chuck Doswell said...

John,

It matters when it comes to the point I'm trying to make. I've specifically talked about those tornadoes most likely to result in fatalities, which generally are the strong-to-violent storms with long tracks, for which NWS warnings are pretty good. I have no objection to improving NWS warnings, but that's not going to result in saving many lives, contrary to a different myth (from the topic of my original post).

As for the fact that NWS warnings contain large areas not in a tornado path - that's yet another topic!

Scott said...

Thank you Chuck, your essay on investing in fatality rates was most interesting and informative and answered many of my questions.

Thanks for your time.

I hope you have a good holiday season.

Anonymous said...

Wow, a whopping 23 comments! Roger, I suggest reading the book "Weather on the Air", by Robert Henson. While not about TV storm chasers per se, the book contains a lot of details on key historical developments in the field broadcast meteorology as well as the media industry in the US in general. It's a good "coffee table" book. Take a look at when you have some free time.