2. Parameters

Stability Assessment » Convective Available Potential Energy (CAPE) Strengths and Limitations

Strengths

  • CAPE is a robust indicator of the potential for deep convection and convective intensity.
  • CAPE provides a measure of stability integrated over the depth of the sounding, as opposed to other stability indices, such as Lifted Index, that use data from only a few mandatory levels.

Limitations

  • The computation of CAPE is extremely sensitive to the mean mixing ratio in the lowest 500 m. For instance, a 1 g/kg increase can increase CAPE by 20%.
  • Since the computation of CAPE is based on parcel theory, it does not take into account processes such as mixing, water loading, and freezing.
  • Surface layer based CAPE computations may underestimate the convective potential in situations with elevated convection.
  • Since CAPE, by itself, does not account for wind shear, it may underestimate the potential for severe convection where strong wind shear is present.