Effects of Entrainment and Water Loading - 2
In contrast to the pair of soundings with equal CAPE on the previous page, soundings A and B on this page have identical vertical profiles of CAPE, but Sounding B is drier above the surface. Sounding A would produce a stronger updraft than Sounding B, but Sounding B would produce a much stronger downdraft.
The entrainment of dry mid-level air into humid air reduces buoyancy, primarily through cooling. Thus it will act to weaken an updraft and strengthen a downdraft.