Sometimes uplifting is caused by a cold front as we just read. Sometimes it is because of the heat of the ground. This happens a lot in cities. Sometimes it's because the land and the sea are so different in temperature.
Most thunderstorms happen in summer.
They also happen in Florida, the Southeast, the southern Rockies and in areas near the Great Plains. There are three parts to the making of a thunderstorm. Individual storm cells start in this stage. Unsteady moist air rises and cools and water vapor condenses to form cumulus clouds. The rising air reaches such a height that precipitation occurs.