How can I create a regional subset?

[blaylockbk]

I've had this question several times...

Is there any way to subset individual areas (e.g., "subgrids") using Herbie?

[blaylockbk]

The easiest way to create a regional subset that I know of is to download the data of interest, then use wgrib2 to create a subset. 

1. You must download the full domain first, then create the subset locally (downloading only a regional subset of the GRIB file would require server-side processing). 
2. Subsetting requires wgrib2; see --small-grib
   • Note: wgrib2 is easily installed on Linux with conda, but not easily installed on Windows.

Herbie does have a helper function to create regional subsets using wgrib2; it's hidden in the Herbie document because it's half-baked. 

Steps:

1. Create Herbie object
2. Download data of interest
3. Use Herbies wgrib2 wrapper to turn the data into a regional subset.
4. Recreate Herbie object, which will find the local file instead of the remote file
5. Open the data in xarray

This is demonstrated here: Herbie Wrapper for wgrib2

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There might be a way to create regional subsets with eccodes, but I haven't investigated that yet. Let me know if you know!

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If you happen to be working with HRRR model data, an alternative to Herbie is to use the HRRR in Zarr format, which I don't have many examples of aside from these:  What about Zarr? — Herbie 2024.3.0 documentation