What are characteristics of a moist, unstable air mass?
ATurbulence and showery precipitation.✓
BPoor visibility and smooth air.
CHaze and smoke.
Why →A moist, unstable air mass is characterized by turbulence (from convective activity) and showery precipitation (cumuliform clouds producing rain showers or thunderstorms). Unstable air rises, cools, and condenses rapidly, producing vertical cloud development (cumulus and cumulonimbus).
The trap →Poor visibility with smooth air, and haze and smoke, both describe stable air, which suppresses vertical development and traps pollutants near the surface.
Field note →The mnemonic: Unstable = Unpredictable (turbulence) + Upward (convection). Stable = Smooth + Smoggy. On the exam, turbulence + showery = unstable.
SOURCE → PHAK Chapter 12, FAA UAG Sample Question 37CHECKED JUL 16ACS III.A.K1MED