There are three main ingredients for any thunderstorm:
Moisture is needed in the atmosphere to form the clouds and rain that makeup a thunderstorm. Here in East Texas, the Gulf of Mexico acts as the major moisture source for most thunderstorms that develop in our area of the country.
Instability is needed to create the rising air that forms thunderstorms. Instability, or unstable air, is created when warm air rises.
A lifting mechanism is also needed to trigger thunderstorms. This aids in the instability in the atmosphere. Lifting mechanisms for thunderstorms include fronts, seas breezes, and mountains.