What is wind shear?

• A. A gradual change in wind with altitude.
• B. A sudden drastic shift in windspeed, direction, or both.
• C. A constant wind with altitude.
• D. A gust that lasts less than a second.

Answer: (B)

Wind shear is a sudden drastic change in wind speed and/or direction over a short distance in the atmosphere. This abrupt change can occur as you move through different layers of air (vertical shear) or across a region (horizontal shear). That sharp distinction is what makes wind shear different from a gradual wind change or a constant wind with altitude. A fleeting gust—especially one lasting less than a second—does not by itself define wind shear, since shear focuses on the rapid spatial change in wind, not just a brief gust. In flight, encountering wind shear can cause quick shifts in airspeed and lift, which can lead to changes in pitch, altitude, or energy state, so it’s a key factor to anticipate near fronts, thunderstorms, jet streams, and during takeoffs or landings.