lcl#

metpy.calc.lcl(pressure, temperature, dewpoint, max_iters=None, eps=None)[source]#

Calculate the lifted condensation level (LCL) from the starting point.

The starting state for the parcel is defined by temperature, dewpoint, and pressure. If these are arrays, this function will return a LCL for every index. This function does work with surface grids as a result.

Parameters:
Returns:

Examples

>>> from metpy.calc import lcl
>>> from metpy.units import units
>>> lcl(943 * units.hPa, 33 * units.degC, 28 * units.degC)
(<Quantity(877.033549, 'hectopascal')>, <Quantity(26.7591908, 'degree_Celsius')>)

See also

parcel_profile

Notes

From [Romps2017], this directly solves for the temperature at the LCL, Eq 22a,

\[T_{LCL} = c [W_{-1}(RH_l^{1/a} c \exp{c})]^{-1} T\]

and the pressure at the LCL, Eq 22b,

\[p_{LCL} = p \left( \frac{T_{LCL}}{T} \right)^{c_{pm} / R_m}\]

where \(a\) (Eq 22d), \(b\) (Eq 22e), and \(c\) (Eq 22f) are derived constants, and \(W_{-1}\) is the \(k=-1\) branch of the Lambert \(W\) function.

Changed in version 1.0: Renamed dewpt parameter to dewpoint

Examples using metpy.calc.lcl#

Advanced Sounding

Advanced Sounding

Advanced Sounding Plot with Complex Layout

Advanced Sounding Plot with Complex Layout

Mountain Problem

Mountain Problem

Sounding Calculation Examples

Sounding Calculation Examples

Upper Air Sounding Tutorial

Upper Air Sounding Tutorial