Near Clayton, New Mexico, July 18, 2009. This thunderstorm’s updraft wasn’t too high—between 4,000 and 5,000 feet from the ground, according to Hill—but it seemed low to Dobrowner. “It almost felt like I could lift my hand up and touch it,” he says. Although this was part of a supercell, says Hill, such isolated storms typically occur further north during the summer.