What is the term for thunderstorms caused by air being lifted by sloping ground?

The term for thunderstorms caused by air being lifted by sloping ground is orographic thunderstorms. This type of thunderstorm occurs when moist air encounters a mountain or hill and is forced to rise. As the air rises, it cools and condenses, leading to cloud formation and precipitation. This process is particularly common in mountainous regions, and the resulting thunderstorms can be quite intense due to the orographic lifting mechanism.

In contrast, frontal thunderstorms occur along weather fronts where two air masses meet, while single-cell thunderstorms are typically isolated systems that can develop in instability. Advection thunderstorms result from warm, moist air moving over a cooler surface, leading to lifting due to temperature differences. Hence, orographic thunderstorms specifically describe the phenomenon linked to sloping terrain, making that answer the most appropriate.