🐛🔨 on zero-size array to reduction operation in lfc when there is no el

[leaver2000]

Description Of Changes

Size check to insure a non-zero sized array prior to calling np.min(el_pressure) > this_lcl[0] which was throwing a ValueError("zero-size array to reduction operation minimum which has no identity").

As a quick example, here is the result of MUCAPE prior to the fix, where the error was caught and nan values were inserted. white represents those missing values.

Post fix; the calculation is using the LCL as the LFC and this is the result.

Checklist

• Closes ValueError: zero-size array to reduction operation minimum which has no identity #3795
• Tests added
• Fully documented

[CLAassistant]

All committers have signed the CLA.

[dopplershift]

Thinking over the logic, not to mention your graphics above, I agree that this is the correct solution. (Contrary to my comment in the issue.)

[dopplershift]

Thanks for the contribution!