lfc

metpy.calc.lfc(pressure, temperature, dewpt, parcel_temperature_profile=None, dewpt_start=None, which='top')[source]

Calculate the level of free convection (LFC).

This works by finding the first intersection of the ideal parcel path and the measured parcel temperature. If this intersection occurs below the LCL, the LFC is determined to be the same as the LCL, based upon the conditions set forth in [USAF1990], pg 4-14, where a parcel must be lifted dry adiabatically to saturation before it can freely rise.

Parameters

  • pressure (pint.Quantity) – The atmospheric pressure

  • temperature (pint.Quantity) – The temperature at the levels given by pressure

  • dewpt (pint.Quantity) – The dewpoint at the levels given by pressure

  • parcel_temperature_profile (pint.Quantity, optional) – The parcel temperature profile from which to calculate the LFC. Defaults to the surface parcel profile.

  • dewpt_start (pint.Quantity, optional) – The dewpoint of the parcel for which to calculate the LFC. Defaults to the surface dewpoint.

  • which (str, optional) – Pick which LFC to return. Options are ‘top’, ‘bottom’, ‘wide’, ‘most_cape’, and ‘all’. ‘top’ returns the lowest-pressure LFC, default. ‘bottom’ returns the highest-pressure LFC. ‘wide’ returns the LFC whose corresponding EL is farthest away. ‘most_cape’ returns the LFC that results in the most CAPE in the profile.

Returns

  • pint.Quantity – The LFC pressure, or array of same if which=’all’

  • pint.Quantity – The LFC temperature, or array of same if which=’all’

See also

parcel_profile()