Ordinary-cell convective storms - Severe Convective Storms and Tornadoes: Observations and Dynamics - page 98

Figure 3.2b. (Top) Altocumulus castellanus over Norman, OK on September 28, 1977 and
(bottom) July 26, 1978. The bases of the clouds are flat and above the boundary layer. The
clouds are also aligned in streets, possibly in response to lifting by bores (photographs by the
author).