The collision of warm moist air from the Gulf of Mexico, dry air from the Southwest, and cold air from Canada creates the conditions for supercell thunderstorms across the Great Plains each spring. These rotating storm systems are capable of producing the most violent winds on the surface of the earth. The United States experiences more tornadoes than any other country — roughly 1,200 per year with the highest concentration in the central Great Plains. But the storms themselves are the spectacle before any tornado forms — towers of cloud building to 60,000 feet in the late afternoon light, wall clouds rotating beneath them, lightning threading through green-tinged air. The Great Plains in May is one of the most electrically alive place on earth.