A stable air mass is most likely to have which characteristic?

• A. Poor surface visibility
• B. Turbulence
• C. Clear skies and good visibility
• D. High winds and gusts

Answer: (A)

Stable air keeps vertical motion to a minimum, so moisture and pollutants tend to stay near the surface. That trapping effect often forms fog or haze, which reduces surface visibility. Turbulence and gusts come from active mixing and are less likely when the air is stable, and while skies can look clear above a shallow layer, fog or low clouds near the ground make visibility poor. So the most likely characteristic of a stable air mass is poor surface visibility.