January 19, 2017


When the Sky Breaks: Hurricanes, Tornadoes, and the Worst Weather in the World. By Simon Winchester. Viking. $22.99.

     Although officially intended for ages 10 and up, Simon Winchester’s When the Sky Breaks has so much well-presented and important information in it that parents will be as eager to read it as will their children. Weather, after all, affects every one of us, every single day, and despite the famous statement that everybody talks about the weather but nobody does anything about it (Charles Dudley Warner, wrongly attributed to Mark Twain), the urge to learn about weather and try to predict it is a strong one. Maybe we cannot do anything about the weather itself, after all, but maybe we can better prepare ourselves for whatever the weather may be.

     Or maybe not. Weather events are far more complicated, hence unpredictable, than most people realize, and Winchester shows just how complicated that is. It was mathematician and meteorologist Edward Lorenz who coined the term “the butterfly effect” to describe major weather changes caused by small, seemingly inconsequential events – although perhaps nothing quite as small as the flapping of a distant butterfly’s wings – and the observation is shown to be correct, time and time again, in Winchester’s book. For example, “Who would have thought that the existence of the Sahara Desert, with its pale and reflective yellow sands and equatorial heat bearing down upon it, would cause disturbances in the atmosphere that could in turn cause storms in the Carolinas or Texas or New York?” Yet this is exactly how hurricanes form, thanks to an event called an African easterly wave (AEW) that is caused by air moving from the Indian Ocean and encountering the heat and aridity of the Sahara. Winchester explains what happens and how, and also why there are not constant hurricanes – here his ability really shines, as he uses the example of a fully fueled car that is ready to go anytime but does not go all the time, because some small thing (the turning of an ignition key) is necessary to start it. That is a small, humdrum version of the butterfly effect, one so common that most readers will likely never have thought of it in these terms – yet it is the very mundanity of the example that helps Winchester clarify the strangeness and enormity of cyclonic storms.

     Winchester humanizes weather forecasting, too. Again in his section on hurricanes, he does not merely present the inevitable discussion of the devastating storm that in 1900 smashed into and nearly destroyed Galveston, Texas – still the deadliest hurricane in U.S. history. What Winchester does is build his story around that of forecaster Isaac Cline, who lived in Galveston and was largely responsible for the erroneous forecasts of the storm’s track – but who was repeatedly right about the storm’s earlier path, which changed in a bizarre way because of “a strange and unseen ripple in the upper atmosphere” that the science of the time could not possibly have known about or understood.

     As the subtitle of When the Sky Breaks indicates, the book discusses tornadoes as well as hurricanes – and also deals with cyclones, the Southern Hemisphere version of hurricanes. The pages about Cyclone Tracy, which hit Darwin, Australia on Christmas Day 1974, are especially harrowing. Like the Galveston hurricane three-quarters of a century earlier, this cyclone “quite unexpectedly…made a sharp right-angled swerve [and] bore down with withering accuracy toward the dead center of Darwin. …Ten thousand houses, 80 percent of the city, were totally destroyed, reduced to matchsticks and pulverized concrete.” The death toll was modest for so intense a storm – 71 people were killed, compared with some 8,000 in Galveston – but “Darwin was brought to its knees,” and did not even have regular communication with the outside world for three days. “In the end, almost the entire city of Darwin had to be evacuated. Forty-one thousand of its forty-seven thousand inhabitants were without home, shelter, water, food, medicine, or communication.” But the city was rebuilt, essentially from the ground up, and today is thought to be cyclone-proof – not that a storm as strong as Tracy has ever tested it. Yet.

     That “yet” matters. The human ability to rebuild after disaster is sorely tested by vast storms, but rebuilding does occur, hopefully with major lessons learned – including those discussed in When the Sky Breaks about severe weather being both predictable and unpredictable. And that has much to do with tornadoes. Winchester accurately describes the tornado as “America’s national storm,” since most of the world’s tornadoes happen in the United States. The conditions under which a tornado will form are well-known, but the actual formation of a particular tornado remains unpredictable – and the speed of formation and movement are such that when a tornado does occur, there is very little time to respond. And safety is harder to come by than in hurricanes: tornado winds are so strong that they cannot be accurately measured, because “even the sturdiest of anemometers, or wind-speed instruments, is invariably destroyed by the strongest tornado.” There are plenty of photos of the destruction wrought by tornadoes and other storms in When the Sky Breaks, but this is not primarily a picture book: it is descriptive and explanatory. The tornado section, for instance, contains a fascinating explanation of why the “accident of geography” of the United States makes tornadoes likelier in the U.S. than anywhere else: the deadliest tornado ever was actually in Bangladesh in 1989, but 14 of the 50 worst have occurred in the U.S. When the Sky Breaks is packed with information, but even with everything scientists and researchers now know, Winchester acknowledges the limitations of meteorology, noting that “little is certain” even though “global forecasting is less of an enigma, less of a throw of the dice, than it once was.” The fascinating material in this book will not make it any easier for readers to decide what clothing to wear the day after reading it, but it will help them understand the vast, interconnected global patterns of which their local weather events, however severe, are just one small part.

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