What forms around a boundary where two contrasting air masses meet?

When two contrasting air masses meet, a boundary known as a front forms. This front can lead to various weather phenomena, including clouds, precipitation, and storms, depending on the characteristics of the air masses involved. Warm, moist air rising over cooler, denser air can create conditions for thunderstorms, while colder air can lead to clearer skies. The interaction at the front is crucial for shaping local weather patterns.