Using Herbie when offline--Loading in already downloaded files

[blaylockbk]

Discussed in #169

By this report, Herbie doesn't work when you don't have an internet connection. The expected behavior is to let Herbie still work when offline and if you have the files already downloaded.

^{Originally posted by tlg7 March 2, 2023}
This is a great piece of software for downloading model data easily and efficiently.

I have directory of HRRR data downloaded already. To read in that data, I use two commands:

# Load the Herbie object
H = Herbie(pstest.strftime("%Y-%m-%d %H"), fxx=0)

# Reads the variable as a dataset.
ds = H.xarray("CAPE:surface", remove_grib=False)

This works well on my own computer, but on an HPC cluster fails, most likely due to internet restrictions.

My question: is it possible to read in the files I already have downloaded without using any internet connection? The files names are saved so that I can't understand them (ex. subset_44ef1277__hrrr.t00z.wrfsfcf00.grib2), or else I would simply call the file with the matching time/variable.

Thanks!

[blaylockbk]

• Herbie will need to skip looking for an index file (use a try...except block??) which it always tries to look for online.
• Herbie should be able to look for local files before needing an internet connection.