The wind turbine wake of a single turbine in complex terrain is analysed using measurements from lidars. A particular focus of this analysis is the wake deficit and propagation. Six scanning lidars, three short-range and three long-range WindScanners, were deployed during the <i>Perdigão 2015</i> measurement campaign which took place at a double-ridge site in Portugal. Several scanning scenarios, including triple- and dual-Doppler scans, were designed to capture the wind turbine wake of a 2 MW turbine located on one of the ridges. Different wake displacements are categorised according to the diurnal cycle. The results show a strong dependence of the vertical wake propagation to the atmospheric stability. When a terrain-induced gravity wave is observed under stable conditions, the wake follows the terrain down the ridge with a maximum inclination of −28°. During unstable conditions, the wake is advected upwards by up to 29° above horizontal.