Preliminary results are presented on the nature of a distinct class of sub‐km high latitude irregularities which can create localized regions of near saturated VHF and fairly intense UHF scintillations in the nighttime auroral F‐region. The unique feature of this class of irregularities is that it is associated not with large scale (several tens of km) organized density gradients in the F‐region but with velocity shears with shear gradient scale lengths ∼10km. The presence of velocity shears was established by EISCAT ion drift measurements, continuous STARE measurements of electron drift and the in‐situ ion drift measurements from the HILAT satellite. Analytical and numerical simulation studies of velocity shear driven Kelvin‐Helmholtz type plasma instabilities are necessary to elucidate the generation mechanism of this class of irregularities.