How can I find out if a value in an area in a dataset exceeds a value?

[sgofferj]

Hi there,

sorry for my rocky language. I'm fluent in general English but lack the specific vocabulary here.
I'm running a free website for stormchasers in Finland as a hobby project and I'm currently moving my rendering process from grads to Python. I already successfully import and plot GRIB data. What I would like to do next is find out if a certain parameter is exceeded in a certain area ideally defined by a shape file. For example, run a test if the Supercell Composite Parameters exceeds 1.5 against the shape files of all districts in Finland. How would I go about this?

Links and pointers would be very welcome!
-Stefan

[mathause]

Maybe this can get you on the way:

import regionmask
import xarray as xr

air = xr.tutorial.open_dataset("air_temperature")

mask = regionmask.defined_regions.srex.mask(air.air)

g = air.air.groupby(mask)

g.max() > 1.5

and https://regionmask.readthedocs.io/en/stable/notebooks/geopandas.html to work with your own shapefile.

Disclaimer: I am the author of regionmask

[sgofferj]

I'll check, thanks!