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.