Which of the following statements is accurate regarding turbulence associated with thunderstorms?

The statement that turbulence can be encountered 20 miles laterally from a severe storm is accurate. Thunderstorms are known to produce significant turbulence not only within the cloud itself but also in the surrounding air. The strength and intensity of thunderstorms can extend far beyond their visible boundaries, meaning pilots may face turbulent conditions even at considerable distances from the storm front. This can pose risks to aviation safety, making it crucial for pilots to be aware of these potential hazards.

The other choices suggest limitations or incorrect assumptions about turbulence related to thunderstorms. Turbulence is not confined to the cloud itself; it can occur in the surrounding areas. Additionally, turbulence associated with thunderstorms can be more severe than clear air turbulence due to the violent updrafts and downdrafts present in storm systems. Furthermore, turbulence can occur at various altitudes, not just high altitudes, as it can result from thermal currents and other factors occurring at lower levels as well.