metpy.calc.cape_cin(pressure, temperature, dewpt, parcel_profile)[source]

Calculate CAPE and CIN.

Calculate the convective available potential energy (CAPE) and convective inhibition (CIN) of a given upper air profile and parcel path. CIN is integrated between the surface and LFC, CAPE is integrated between the LFC and EL (or top of sounding). Intersection points of the measured temperature profile and parcel profile are linearly interpolated.

  • pressure (pint.Quantity) – The atmospheric pressure level(s) of interest. The first entry should be the starting point pressure.
  • temperature (pint.Quantity) – The atmospheric temperature corresponding to pressure.
  • dewpt (pint.Quantity) – The atmospheric dew point corresponding to pressure.
  • parcel_profile (pint.Quantity) – The temperature profile of the parcel

  • pint.Quantity – Convective available potential energy (CAPE).
  • pint.Quantity – Convective inhibition (CIN).


Formula adopted from [Hobbs1977].

\[\text{CAPE} = -R_d \int_{LFC}^{EL} (T_{parcel} - T_{env}) d\text{ln}(p)\]
\[\text{CIN} = -R_d \int_{SFC}^{LFC} (T_{parcel} - T_{env}) d\text{ln}(p)\]
  • \(CAPE\) Convective available potential energy
  • \(CIN\) Convective inhibition
  • \(LFC\) Pressure of the level of free convection
  • \(EL\) Pressure of the equilibrium level
  • \(SFC\) Level of the surface or beginning of parcel path
  • \(R_d\) Gas constant
  • \(g\) Gravitational acceleration
  • \(T_{parcel}\) Parcel temperature
  • \(T_{env}\) Environment temperature
  • \(p\) Atmospheric pressure

See also

lfc(), el()