What type of conditions does clear air turbulence typically occur near?

Clear air turbulence generally occurs near jet streams due to the unique atmospheric conditions associated with these high-altitude air currents. Jet streams are fast-moving areas of air in the upper atmosphere that can create sharp gradients in wind speed and direction. As aircraft transition into or out of these areas of strong wind, they may encounter turbulence resulting from the shearing effects of the wind variations.

Clear air turbulence is particularly significant because it can happen in otherwise clear air, away from clouds or storms, making it challenging for pilots to detect and anticipate. The turbulence arises from the interaction of the airflow patterns at different altitudes and the mixing of different air masses, which is characteristic of locations near jet streams. The distinct wind patterns contribute to the turbulence that is often unexpectedly encountered at cruising altitudes.

While other options mention conditions associated with turbulence, they are not closely linked to clear air turbulence specifically. For instance, temperature inversions close to the ground and stable high-pressure ridges can affect local weather but are not the predominant areas for the clear air turbulence phenomenon. Thunderstorms can certainly produce severe turbulence, but this is different from the clear air turbulence associated with jet streams.