Ordinary-cell convective storms - Severe Convective Storms and Tornadoes: Observations and Dynamics - page 99

Figure 3.3. Schematic illustrating forced lift over a surface front, an outflow boundary, or
orography. Vertical cross section showing air flow (streamline) and cold side of front or
outflow boundary, or area between the surface of the rise in ground level and the surrounding
ground level (hatched area).
Figure 3.4. Illustration of entrainment of environmental air into a cloud (curled streamlines
into curling, rolling, cumulus elements) on July 2, 2011 in Boulder, CO. Air enters the cloud
base from below and from the sides. As a result of entrainment, the mass flux of air detraining
from the cloud at the top exceeds the mass flux into the cloud base below (photograph by the
author).