There s plenty of water in the air, and no shortage of sunlight and fronts to get those currents going. Nonetheless, thunderstorms are relatively infrequent. Even those places that get thundered on one hundred days year don t get thundered on the other 265 days. The average storm lasts an hour or two, which means only two hundred hours or eight days out of the one hundred are actually thundering. So, even in the thunderstorm capital of Florida, it s actually thundering only about 2 percent of the time during an average year.
Most people spend more of their lives in the shower than they do hearing thunder.
Clearly, atmospheric conditions have to be just right for thunderstorms to develop. The necessary condition is called instability , the opposite of stability . A bowling ball sitting in a ditch is stable give it a shove, and it will settle back into the ditch. A bowling ball balanced on roof s unstable give it a kick and off it goes. Like a bowling ball, the atmosphere can be stable or unstable.