Wednesday, May 25, 2011

Pick your favorite bogus "explanation"

Evidently, 2011 is going to be a bad year for tornado fatalities. A really bad year. You have to go back to 1947 to find a single tornado that killed more people than were killed on 22 May in Joplin, MO. We're approaching 500 fatalities with much of the tornado season yet to come, and the last time we had more than 500 fatalities in a single year was 1953.

1953 was a terrible year, with three major single violent tornadoes: Waco, TX on 11 May (114 fatalities), Flint, MI on 08 June (116 fatalities), and Worcester, MA on 09 June (94 fatalities), as well as many lesser outbreaks. At the time, there was speculation that the severe weather was being "caused" by the nuclear explosions going on as the United States flexed its cold war muscles. The media did what the media always do: spread wild speculation about the influence of atomic tests on the weather without regard for its scientific validity. Such talk went on for years, to be raised again in 1957 (another big year for tornadoes, but without the extreme fatality count).

Almost every time there are major tornado events, the media seem compelled to ask the inevitable stupid question: what's causing this wild weather? The production crews descend on National Weather Service offices with reporters and cameras rolling, endlessly asking the same ignorant questions. The media simply can't extricate themselves from their own ignorance, being inclined to believe that there must be something to "explain" what's going on with some simple phrase if they can just get their "expert" to utter it as a sound bite. Whenever severe weather happens, it's a "freak" storm, that struck without warning, sounded like a freight train, looked like a war zone afterward, occurred with a clash of air masses, etc. The media prefer hackneyed phrases to substance, it seems.

The tornado threat varies widely from year to year. In meteorological terms, every year is different, and so it's easily understandable that some years have many tornadoes, and other years not so many. It's called "interannual variability" and for tornadoes, our understanding of that variability is troubled with many issues regarding how accurately we know the facts about the tornadoes that happen.

In 2011, the popular "exotic" media explanations for tornado outbreaks include: La Nina, global warming, global cooling (!!), god's wrath, and local terrain features that are being blamed for these "weather gone wild" events. From the perspective of someone who's spent a career looking at tornado occurrence records, one thing is abundantly clear: these events require no exotic "explanation". The past is the key to the present and future. By looking at data from the past, it becomes clear that events similar to what have been going on this year have happened before (most recently in 1953) and they will happen again (although we can't yet predict exactly when and where). Major disasters occur when violent tornadoes track through populated areas. Since most tornadoes spin out their existence over open country or thinly populated areas, we don't have major tornado disasters every year. Really big tornado outbreaks happen at intervals of roughly 20-40 years or so. The vulnerability in any given year is increasing because of our increasing population at risk (suburban "sprawl" and increasing recreational use of some areas), but it seems that this has been mostly offset by better forecasts and warnings, improved methods of communication of the threat when it develops, and infrastructure enhancements promoting natural hazard preparation (at least until the past decade or so). But those improvements have not eliminated entirely the threat for high fatality counts, as events this year have demonstrated.

When these big fatality counts occur, it's mostly a matter of bad luck. For the most part, we've had good luck for several decades, but it seems this year that our good luck has deserted us. But there's no need to resort to "exotic" explanations for every bad event. Specific reasons for individual fatalities can be difficult to figure out after the event, since those killed are unable to explain to us what happened to them. In some cases, contributing factors can be deduced or nearby survivors may be able to tell the tale, but in other cases, it's simply not possible to know what contributed to the misfortune. We're now in the situation that more than 50% of modern casualties of late (at least in lesser tornado events) have been associated with flimsy mobile homes. The poor, the handicapped, the elderly -- all are particularly vulnerable in tornado situations. People can be killed in well-constructed homes when they experience violent tornadoes that simply sweep those homes away if they have no tornado-resistant shelter (as in much of the South, where basements and tornado shelters are relatively rare).

Major events causing many deaths are typically well-warned for by the National Weather Service. Nevertheless, when strong-to-violent tornadoes pass through populated areas, people almost certainly will be killed, even when warnings are issued with more than enough lead time. The reasons for that are complex and not entirely understood, but those fatalities are almost never the result of "it struck without warning" in the sense that a warning was not issued with useful lead time. Sadly, this loss of life continues to be inevitable despite our best efforts. No special explanation is necessary, beyond the bad luck of being in a tornado's path without anywhere to go.


Anonymous said...

Why have you put exclamation point after global cooling?

Chuck Doswell said...

Because it takes a great deal of something profoundly unscientific to believe that the global temperature is decreasing right now!

Frank said...

Had a rather famous, young, former OU football player tweet this as a cause of this, "I think the U.S. needs to step back and take a look at what we're doing and how we're living. Bc there are too many disasters happening!!" and this "Too much disaster at once means God is trying to show us something. I pray we figure it out soon. We have to stop going through this!!" You can just imagine my consternation, reply, and immediate unfollowing on twitter.
Frank Keller

Anonymous said...

So what's at the root of this fear mongering, sensationalism, and stupid assertions from the media? Do you think if this kind of reporting didn't sell soap, it would remain on the air? If, instead, factual, well-investigated, in-depth reporting took its place, that people would watch? No. Too many people either have ADHD or are not intelligent enough to follow information beyond a sound bite. And that's just the way governments like them.

Sorry to say, but it seems like you're like the little Dutch boy with his finger in the dike, Chuck.

Chuck Doswell said...

Anon ...

It may be true that it's hopeless to try to change the media's perspective or to educate the public. But that doesn't mean I have to like it. These blogs aren't going to change the world, but they allow me to get this off my chest. And perhaps they influence a few folks to think things through a bit more. If I say nothing, I implicitly condone what's happening. Would you rather I quit?

SuperstreamingFacebookingTweetingStreamingStormchaser said...

I sure hope you don’t quit Chuck! But if you want to get your message out you need to get a mobile internet connection, an SPC bull eyes, find Reed Timmers Imap location, a Facebook/Twitter account, streaming dome cam, streaming dash cam, streaming rear view cam, streaming dash cam showing your face, ChaserTV account(better have GPS and switch to Imap or nobody will see your stream!), storm track account (100 post count required before you are a certified storm chaser!) , Hail cages!! Tanks, rockets, drones and remote controlled hot air balloons to send into tornado’s for scientific purposes! A account (because it’s for chasers created by chasers!! WTF!!) , A random photo with the dominator!!! If you get one with D2 then you are bumped to veteran chaser!!! And remember to frantically post what you are doing at all times on twitter!! And then maybe people will listen to you! Oh and I forgot, you will need a Credit Card to max out /on gas/ChaserTV/aircard/vehicle (wear and tear)/motels/food/) during the chase season but don’t worry because all of the money you will make off of Imap streaming will cover that!!!! Just a reminder if you are filming a tornado be sure to say “listen to the roar” and “ohhhh I hope nobody was home!!”

Anonymous said...

Why is La Nina an exotic explanation, especially because it's given as a contributing factor in the recent tornadoes, not the sole explanation?

In California, people regularly talk about El Nino or La Nina years so La Nina seems very commonplace and not exotic at all. A La Nina episode/year is a fairly common event (every 5 years or so), though not as common as an El Nino episode/year. It merely refers to a sustained drop in the sea surface temperature in the Pacific (roughly from South America to the International Date Line) and the weather patterns that typically result from it. This drop in surface temperature causes the Pacific trade winds to blow more strongly than usual, pushing the sun-warmed surface water farther west and away from the equator. This cold surface water in western South America (and resulting dry air) affects the weather patterns in the US. It's very noticeable and consistent in parts of the west coast and the southwest, though not as noticeable as it is in South America. La Nina winters are always dry in the southwest USA.

The La Nina/El Nino oscillation (aka the Southern Oscillation) was first noticed in the 16th Century and almost certainly occurred before then.

Craig Setzer said...

Enough blaming the media. There are many willing accomplices in the scientific community that give the media a story. For example in the Miami Herald today (excerpt below), the story is sourced by four different scientific authorities. Unless the scientific community speaks with a common voice on an issue either requiring or not requiring an explanation, the media will continue to report the most sensational of those varied sources. No one reports on the dog that didn't bite. The media would not report on a bogus explanation if it weren't suggested by scientists first.
True the media asks "Why?", but look at the answers they are getting.
Tornadoes! Floods! Droughts! Scientists say it's global warming

McClatchy Newspapers

WASHINGTON -- The deadliest tornadoes in decades. Severe flooding on the Mississippi River. Drought in Texas, and heavy rains in Tennessee.

What's up with the weather?

Scientists say there are connections between many of the severe weather events of the past month and global warming.

"Basically, as we warm the world up, the atmosphere can hold more moisture in it," said Anne Jefferson, an assistant professor in the geography and Earth science department at the University of North Carolina, Charlotte.

"Weather patterns that used to be limited to the South move farther north now," she said. "Both of those things together will increase the frequency with which we see these big rainstorms, and those are likely to increase flooding in the future."

Flooding on the Mississippi has become more frequent and more extensive since about 1950, Jefferson said. This year's huge flood was created by snowmelt and rain-on-snow in the upper Mississippi River basin, and very intense rain in its middle regions.

"Climatically we have a higher frequency of rain-on-snow events, a real recipe for flooding," she said. "Also you're getting more warm moist air from the Gulf of Mexico farther north up the Mississippi. It's both a warming and, more so, the fact that the weather patterns have changed and are projected to continue to change, so the precipitation patterns are changing."

All of these changes are part of the general shift in the world's climate known as global warming - primarily the result of billions of tons of heat-trapping gases released into the atmosphere from burning fossil fuels, as well as deforestation.

Chuck Doswell said...

Anon ...

I suggest you read my paper that addresses the topic of hypothesized connections between ENSO (which includes La Nina) and tornado activity:

For the most part, when this item is discussed in the media, its role as a contributor to events is transformed into the "cause" of the events. It's difficult with existing data to establish (with high statistical confidence) the connection between ENSO and tornadoes, in part because the causal linkages are not necessarily well understood.

Chuck Doswell said...

Craig ...

I disagree that I have done enough media bashing! The fact that they can search out some academic somewhere, often with marginal credentials regarding the topic, to say something that is of limited scientific substance is not to their credit.

I've given up trying to work with the media after literally decades of trying. Even on the rare occasion when they actually use something I said that has some merit (rather than an offhand comment transformed into the sole sound bite from an interview that went on for hours), it's drowned in a sea of misinformation from other media "coverage".

Sure, some of the folks from whom they obtain quotes may be contributing to the problem, but (a) many of those quotes are misleading and taken out of context, and (b) they often are misquoted! When I see someone I know saying something stupid in a media interview, my first reaction is to assume that (as in my typical experience) this statement is not necessarily what was intended by the interviewee.

Most modern journalists suck, imho!!

Chuck Doswell said...

One more thing, Craig ... science will never speak with a completely united voice. That's not how science works. Scientists disagree with each other all the time!!

The media's idea of "fair and balanced" reportage apparently is to seek out two people with diametrically opposing viewpoints and let them duke it out. As is the case with the AGW "debate' this actually misinforms the public, because it puts the AGW deniers on equal footing with the supporters of the IPCC reports, when the real situation is that they're a tiny minority within that scientific discipline.

John Monteverdi said...

To Anonymous (must you remain Anonymous...I find that kind of surreptitious). The impact of La Nina CAN be used to explain general weather patterns, not specific events like supercell thunderstorm tornadoes. Those latter depend upon the coexistence of ingredients related to wind shear, buoyancy, features on weather maps (such as outflow boundaries) that are unrelated to the general weather patterns. I think it can be argued that the patterns we had this spring ARE related to sea-surface temperature patterns in the eastern tropical Pacific, even as the latest cold episode is abating. However, before you think this is an agreement with your comment...remember that we've had La Nina events recently that did NOT have such a prolific set of strong supercell tornado events.

Also, long after all who read these posts are gone from the planet, it may be proven that that the plethora of supercell tornado events this year (and it would have to happen repeatedly for many years in the next 50) ARE unusual...and ARE related to increasing water vapor going into the lower atmosphere due to Global Warming (please...Global Cooling? Who actually thinks that?). But we'll be long gone...and you simply cannot take one bad year and extrapolate that as evidence that the climate has changed (even if it has) statistically. And you simply can NOT prove that any increase in tornadoes in the late 20th century to present time is related to a climate change at all.

Anonymous said...

So... Does global warming have anything to do with it or not? Can you elaborate? Thank you!

Chuck Doswell said...

Anon ...

Damned if I know whether global warming has anything to do with this or not. I can't imagine how one might go about trying to provide any meaningful evidence one way or the other. Trying to connect global climate change to specific weather events is just not possible. Some people have been trying, evidently unsuccessfully, to get this across for several years.

Jerome said...

I think the correlation of ENSO to severe weather is in its infancy. Meterologist Joe Aleo uses the total number of CONUS tornados as well as the severity, and he has had some success. The obvious problem from a statistical point of view is that until very recently we lacked the tools to identify and track severe weather outbreaks. For instance, if a supercell developed somewhere over the High Plains in 1928 and dropped an F-4 tornado it isn't inconceivable that it never got reported.

Also, not all La Ninas are the same. And this year, a negative AO combined with a waning strong La Nina set up a weather pattern that allowed persistently cool air masses from the northern Mid Latitdues to penetrate equatorward. The higher elevations in the Far West and Rockies have gotten once in a generation type snowfall and rain, while the southern Plains remain in a severe drought. I don't think we shall see similiar synoptic weather patterns like this anytime soon.

I remember one long range forecaster late last autumn predict that the Spring of 2011 will be similar to the Spring of 1974 based on the ENOS analog. He forecasted both the flooding in Austrailia and the high number of North American flooding and severe thunderstorms on this one analog.

Chuck Doswell said...


Establishing a correlation between ENSO and tornado reports is not equivalent to showing cause and effect between ENSO and tornadoes. Further, as shown in a paper by me in the Electronic Journal of Severe Storms Meteorology, even producing a statistically meaningful correlation is problematic, largely owing to sample size issues in reported tornado records.

Chuck Doswell said...

Just for the record, for many years various people are quoted in the media as saying this year's "freak weather" is due to ENSO, or the PDO, or whatever. They treat this as if each of these long-term oscillations (over periods of several years)is the same and exists in some sort of meteorological vacuum. These are quasi-periodic cycles that are embedded within the total general circulation.

That general circulation includes other quasi-periodic oscillations, no doubt including some that have yet to be identified. There are various other inputs to the general circulation interacting with these cycles and so the events of a particular period likely are connected to many more than one or two quasi-periodic oscillations.

To attribute the weather to any one (or two) of them is pretty much extreme oversimplification. These cycles may be contributing factors, of course, but by themselves do not determine the weather!!