Jeff Ehmsen moved to Baltimore from Southern California. "We pretty much never get thunderstorms there," he says. Since landing in Mobtown, he's "come to appreciate them as part of the seasonal cycles, but wondered what explains them." I love T-storms, too. Their beauty and drama are fueled by our heat and humidity. Moist air, buoyed by solar heating or clashing fronts, rises through colder air. The updrafts generate electric fields, lightning and thunder. Cooling aloft condenses water vapor, which falls as rain and hail.