text: As with most parameters used in meteorology, there are some caveats to keep in mind, one of which is what CAPE represents physically and in what instances CAPE can be used. One example where the more common method for determining CAPE might start to break down is in the presence of tropical cyclones (such as tropical depressions, tropical storms, or hurricanes). 
  The more common method of determining CAPE can break down near Tropical Cyclones because CAPE assumes that liquid water is lost instantaneously during condensation. This process is thus irreversible upon adiabatic descent. This process is not realistic for Tropical Cyclones (TC for short). To make the process more realistic for Tropical Cyclones is to use Reversible CAPE (RCAPE for short). RCAPE assumes the opposite extreme to the standard convention of CAPE and is that no liquid water will be lost during the process. This new process gives parcels a greater density related to water loading. 
  RCAPE is calculated using the same formula as CAPE, the difference in the formula being in the virtual temperature. In this new formulation, we replace the parcel saturation mixing ratio (which leads to the condensation and vanishing of liquid water) with the parcel water content. This slight change can drastically change the values we get through the integration. 
  RCAPE does have some limitations, one of which is that RCAPE assumes no evaporation keeping consistent for the use within a TC but should be used sparingly elsewhere.
  Another limitation of both CAPE and RCAPE is that currently, both systems do not consider entrainment.