What are characteristics of a moist, unstable air mass?

Explanation

Moist, unstable air rises readily once lifted, building cumuliform clouds; as PHAK Ch. 12 describes, that produces turbulent (bumpy) air and showery precipitation, while visibility is usually good outside the showers. Poor visibility with smooth air, and haze or smoke, are characteristic of stable air, where pollutants and moisture stay trapped near the surface.