Which meteorological phenomenon is most likely to cause significant low level wind shear?

Thunderstorms are a significant meteorological phenomenon known for causing low-level wind shear due to their powerful updrafts and downdrafts. Within a thunderstorm, the intense vertical motion can result in strong changes in wind speed and direction over short distances. As air rises rapidly within the storm, it can create turbulence, leading to varying wind characteristics, especially at lower altitudes.

In contrast, clear air and sunny weather typically do not produce the same levels of turbulence or wind shear, as they are generally stable conditions. High altitude wind currents, while they may influence weather patterns, do not directly lead to the low-level wind shear associated with thunderstorms. Thus, the presence of thunderstorms is the primary factor that contributes to the significant wind shear experienced at lower altitudes.