What condition indicates that low-level wind shear is always present?

Low-level wind shear refers to a change in wind speed or direction over a short distance, typically found close to the ground. It is particularly significant in relation to aviation safety because it can adversely affect aircraft performance, especially during takeoff and landing.

A downburst is a concentrated downdraft that originates from a thunderstorm, resulting in a strong and rapid descent of wind that spreads out upon reaching the ground. Downbursts are a specific type of wind shear event, as they disrupt the normal wind patterns near the surface and can create hazardous conditions for aircraft. Due to their nature, downbursts are associated with significant wind shear, making it nearly certain that when a downburst occurs, low-level wind shear is also present.

In comparison, while thunderstorms can be related to wind shear, not all thunderstorms produce downbursts, and therefore they do not guarantee low-level wind shear. Fog and hail, while weather phenomena associated with some storms, do not inherently indicate the presence of wind shear.