How to use this plot
Make sure you have the required datafields (air_pressure, ertel_potential_vorticity)
You can use it as is by appending this code into your mswms_settings.py:
from mslib.mswms.mpl_lsec_styles import LS_DefaultStyle
register_linear_layers = [] if not register_linear_layers else register_linear_layers
register_linear_layers.append((LS_DefaultStyle, "ertel_potential_vorticity", "ml", [next(iter(data))]))