low-level wind shear alert system

low-level wind shear alert system (LLWAS)

A system to advise and warn pilots of wind shear near the surface. It consists of an array of anemometers that reads wind velocity and direction around the airfield and signals sudden changes that indicate wind shear. The LLWAS is designed to detect low-level wind shear conditions around the periphery of an airport. Its detection capability is restricted to within this area. At airports equipped with LLWAS, controllers are provided with gust front wind shear information. Controllers will provide this information to pilots by giving them the airport wind followed by the boundary wind (e.g., “Wind shear alert, airport wind 250 at 10, south boundary wind 170 at 25”).