most_unstable_cape_cin#

metpy.calc.most_unstable_cape_cin(pressure, temperature, dewpoint, **kwargs)[source]#

Calculate most unstable CAPE/CIN.

Calculate the convective available potential energy (CAPE) and convective inhibition (CIN) of a given upper air profile and most unstable 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 logarithmically interpolated.

Parameters:
Returns:

  • pint.Quantity – Most unstable Convective Available Potential Energy (CAPE)

  • pint.Quantity – Most unstable Convective Inhibition (CIN)

Examples

>>> from metpy.calc import dewpoint_from_relative_humidity, most_unstable_cape_cin
>>> from metpy.units import units
>>> # pressure
>>> p = [1008., 1000., 950., 900., 850., 800., 750., 700., 650., 600.,
...      550., 500., 450., 400., 350., 300., 250., 200.,
...      175., 150., 125., 100., 80., 70., 60., 50.,
...      40., 30., 25., 20.] * units.hPa
>>> # temperature
>>> T = [29.3, 28.1, 23.5, 20.9, 18.4, 15.9, 13.1, 10.1, 6.7, 3.1,
...      -0.5, -4.5, -9.0, -14.8, -21.5, -29.7, -40.0, -52.4,
...      -59.2, -66.5, -74.1, -78.5, -76.0, -71.6, -66.7, -61.3,
...      -56.3, -51.7, -50.7, -47.5] * units.degC
>>> # relative humidity
>>> rh = [.85, .65, .36, .39, .82, .72, .75, .86, .65, .22, .52,
...       .66, .64, .20, .05, .75, .76, .45, .25, .48, .76, .88,
...       .56, .88, .39, .67, .15, .04, .94, .35] * units.dimensionless
>>> # calculate dewpoint
>>> Td = dewpoint_from_relative_humidity(T, rh)
>>> # calculate most unstbale CAPE/CIN
>>> most_unstable_cape_cin(p, T, Td)
(<Quantity(4703.77308, 'joule / kilogram')>, <Quantity(0, 'joule / kilogram')>)

Notes

Only functions on 1D profiles (not higher-dimension vertical cross sections or grids). Since this function returns scalar values when given a profile, this will return Pint Quantities even when given xarray DataArray profiles.

Examples using metpy.calc.most_unstable_cape_cin#

Advanced Sounding Plot with Complex Layout

Advanced Sounding Plot with Complex Layout

Sounding Calculation Examples

Sounding Calculation Examples