If you have enough data, you’d likely find that today’s terrible weather occurred sometime in the past. With regard to tornadoes, April and May of 2011 look a lot like May and June of 1953. Given the huge amount of money, technology and time we now devote to warning people about nature’s most intense cyclones, the 2011 fatality figures appear to be very disturbing, because they are so similar to those in the big storms 58 years ago.
Both years saw major storms (F4 or F5 on the F0-F5 Enhanced Fujita scale) plow very long paths through densely populated territory. One hundred fourteen people perished in Waco, Texas, midday on May 11, 1953, followed by 116 in Flint, Mich., on June 8, and 94 in Worcester, Mass., June 9. The Flint and Worcester tornadoes were very likely caused by the same long-lived supercell thunderstorm; similarly a single storm with a 300 mile path spun up several very lengthy and powerful tornadoes over Alabama this year. In Tuscaloosa, home of the University of Alabama, over 40 were killed.
The death count for the Joplin tornado on May 22 is currently up to 123, making it the worst single storm since two that occurred on successive days in 1936, with 216 fatalities in Tupelo, Miss., on April 5, and 203 in Gainesville, Ga., the next day.
These numbers aren’t very different from one another. So are we throwing an inordinate amount of money into our detection and dissemination system and getting very little in return?
In a word: no. Despite 2011, there’s strong evidence that we are saving a tremendous number of lives with modern technology.
After the 1953 disasters, developers of weather radar convinced Congress to support a national network of detectors known as the WSR-57 (for 1957), a very acceptable machine for picking up tornadoes capable of causing significant damage. By the mid-1970s, WSR-57’s pretty much covered the tornado-prone regions of the nation.
An interesting thing happened to tornado frequencies. Before the WSR-57 went online the number of reported tornadoes averaged about 500 per year nationwide. By the time the network was complete, we leveled out around 800. Tornado death frequency — the number of fatalities per million — dropped precipitously. This was an unqualified technological success.
In the late 1980s we deployed the new Doppler radar, the WSD-88, which can actually track the movement of air within a storm (and therefore pinpoint a tornado vortex). Tornado numbers soared, thanks in large part to the detection of hundreds of “F0” twisties that might knock over an untethered trailer or the sign at Bob’s Grille in Nags Head (EAT AND GET THE HELL OUT). We now average over 1000 per year, a number that has been constant since the Doppler network went national. Death frequencies dropped a bit more, but not at much as they did from the WSR-57, which picked the “low hanging fruit.” While still saving more lives, we are also detecting more weenies.
Are there really more tornadoes? If that were true, then the number of strong ones that people notice (unfortunately by hindsight) without or with radar — F3 through F5 — should be going up. Obviously not:
Several factors contributed to this year’s horrible figures. One is general awareness. Neither Joplin nor north central Alabama are as tornado-prone as the Oklahoma-Texas “tornado alley.” The tornado drill just isn’t high up on today’s to-do list.
In 1999 Oklahoma City experienced an extreme F5 tornado — and the most powerful one in that class that has ever been measured — that barreled a long path through much of its suburban sprawl. Death toll: 36.
Oklahoma City is tornado-nuts, as well it should be. The National Severe Storm Laboratory, which does a lot of field research, is located there for a very good reason. Television stations compete in storm tracking and many of them have their own Doppler radars. In the absence of modern technology and hyper-awareness, that storm could have easily killed a thousand.
Tuscaloosa and Joplin, while hardly tornado-free, are a ways off the usual major axis of destruction. Joplin is also very close to the Ozarks, whose rough surface clearly makes the state of Missouri an island in the annual tornado tsunami. No one in either city is constantly worrying about having their home pulverized like they do in Oklahoma City every time the dewpoint gets above 75 degrees.
The bad news is that we have yet to succeed in preventing large numbers of fatalities in built-up areas away from the tornado culture when an F5 shows up. But the remarkable and good news is that we have cut the frequency of tornado fatalities, in deaths per million population, by at least fourfold in the past century.
Despite our technology, monster storms will continue to get loose in cities where people don’t perseverate on tornadoes. I am sure that there will be a lot of discussion in the weather business about how to prevent a repeat of 2011, but, on that one, this old weather-geezer is stumped.