What is a defining condition of a stable atmosphere?

A stable atmosphere is primarily characterized by limited vertical motion. In a stable atmosphere, air parcels are less likely to rise or mix vertically, which restricts the development of convection currents that are essential for fire behavior. This stability generally occurs when warmer air is trapped above cooler air, preventing the warmer, less dense air from rising. Consequently, the limited vertical motion can suppress fire growth and intensity because fire relies on updrafts to spread.

In contrast, heightened fire intensity, increased cloud cover, and enhanced convection currents typically indicate unstable conditions where vertical movements in the atmosphere contribute to more dynamic fire behavior and potentially increased fire intensity.