Nesbitt, who is a professor at the University of Illinois at Urbana-Champaign, had dedicated much of the last 15 years to studying the freakish storms of this sleepy agricultural region. He first became fascinated by them in the early 2000s, when a NASA satellite tentatively identified them as the largest and most violent on Earth. “We knew about the Great Plains, the Sahel,” Nesbitt said. But this appeared to be another world. Radar images suggested cloud structures dwarfing those of Tornado Alley or Ganges Plain, many of them materializing in as little as 30 minutes. (Thunderstorms typically develop over the course of several hours.) And yet in the years since, little reliable data had emerged. Many in the meteorological community felt the storms were simply too remote and too dangerous for a controlled study. “The only thing the scientific community knew for certain,” Nesbitt said, “was that these things were monsters.”
Nesbitt had traveled to Córdoba Province because he felt the weather patterns might offer clues into the enduring riddle of why certain storms grew unexpectedly into cataclysms. In the United States, which is home to the most extensive weather forecasting infrastructure in the world, around a third of severe weather predictions still prove wrong — not only about timing and location but also size, duration and intensity. The false-alarm rate for tornadoes continues to hover at about 70 percent, while the average warning time has only increased from about 10 minutes in the mid-1990s to 15 minutes today. Satellites and supercomputer modeling have greatly improved the detection of large-scale phenomena — uncertainty about a hurricane’s path at 48 hours out, for example, has decreased by 30 percent since Katrina — but the more routine, and nevertheless destructive, storms that impact rural provinces and towns continue to erupt with little warning. Today few countries outside the United States and Western Europe even attempt to forecast extreme weather. In a place like Córdoba, prediction has often fallen to amateurs like Lenardon, who, tasked with the safety of their communities, must puzzle from the air what the sparse and unreliable infrastructure misses.
But it was a job that had grown considerably more difficult in recent years. As Lenardon explained to Nesbitt, the region was beginning to see ever more storms escalate in both size and intensity. “Before, it was impossible for me to imagine more than one damaging storm a year,” he said. “Now I expect three or four.” For Nesbitt, it was exactly these abnormal qualities of growth and destructiveness that made the sierras instructive. He believed that if he could chance a closer look inside one of the superstorms — mapping its internal wind structure and the conditions that gave it life — he might be able to produce a blueprint for predicting others like it, in Argentina and worldwide. “Climate-change models are predicting all this bad weather,” Nesbitt said. “But no one knows exactly what that weather will look like.” In Córdoba, he thought he’d discovered a laboratory for studying it — a rugged, poorly mapped swath of ground the size of Wisconsin, which might offer a glimpse of the storms to come.