Salina, Kansas

Out here in storm country, one storm can drop tornado after tornado. Meteorologists call that a tornado family, a string of twisters spawned by the same supercell. The secret is a rotating updraft called a mesocyclone. As one tornado matures, cool air from the rear-flank downdraft wraps around it and chokes off its warm fuel, a process called occlusion. The old rotation dies, but the storm doesn't quit. A fresh updraft spins up just to the southeast, builds a new mesocyclone, and a new tornado can form along the same line. The storm cycles, again and again, which is why these are called cyclic supercells. Before the 1970s, a family like this was often mapped as one impossibly long tornado. Better radar and survey work finally showed the truth: not one monster, but a relay team.

Out here, your nose knows a storm before the sky does. As the wind shifts, you catch a sharp, clean, almost metallic zing. That's ozone, named in 1840 from the Greek ozein, meaning 'to smell.' Lightning rips nitrogen and oxygen molecules apart, and the storm's downdrafts carry that scent down to nose level. Then comes the sweet, earthy smell of the first rain on dry ground. Scientists call it petrichor, a word coined in 1964 by Australian researchers Isabel Bear and Richard Thomas. The earthy note inside it is geosmin, made by soil bacteria called Streptomyces while they wait out the dry spell. Rain bursts tiny bubbles in the dirt and flings it into the air. Afterward, a severe storm leaves its own bouquet: splintered green wood, churned wet earth, and sometimes the bite of a broken gas line. The alley smells like a storm.