http://climate.ncsu.edu/edu/k12/.thunderstorm
Thunderstorm develops under certain circumstances so depending on for instance variables like heat moisture and wind they can either die out quickly or sustain itself longer.
Typically, if there is little wind shear, the storm will rapidly enter the dissipating stage and 'rain itself out',[8] but, if there is sufficient change in wind speed and/or direction, the downdraft will be separated from the updraft, and the storm may become a supercell, where the mature stage can sustain itself for several hours.[12]