storm_relative_helicity¶

metpy.calc.storm_relative_helicity(u, v, heights, depth, bottom=<Quantity(0, 'meter')>, storm_u=<Quantity(0.0, 'meter / second')>, storm_v=<Quantity(0.0, 'meter / second')>)[source]

Calculate storm relative helicity.

Calculates storm relatively helicity following [Markowski2010] 230-231.

$\int\limits_0^d (\bar v - c) \cdot \bar\omega_{h} \,dz$

This is applied to the data from a hodograph with the following summation:

$\sum_{n = 1}^{N-1} [(u_{n+1} - c_{x})(v_{n} - c_{y}) - (u_{n} - c_{x})(v_{n+1} - c_{y})]$
Parameters: u (array-like) – u component winds v (array-like) – v component winds heights (array-like) – atmospheric heights, will be converted to AGL depth (number) – depth of the layer bottom (number) – height of layer bottom AGL (default is surface) storm_u (number) – u component of storm motion (default is 0 m/s) storm_v (number) – v component of storm motion (default is 0 m/s) pint.Quantity, pint.Quantity, pint.Quantity – positive, negative, total storm-relative helicity