Error when attempting to access NCEP weather model forecasts

[StantonLanham]

Describe the bug
Getting a 404 error when attempting to retrieve weather model forecasts

HTTPError: Error accessing https://thredds.ucar.edu/thredds/ncss/grib/NCEP/GFS/Global_0p5deg/Best/dataset.xml
Server Error (404: 404)

To Reproduce
Steps to reproduce the behavior:

import pandas as pd
import datetime
from pvlib.forecast import GFS
latitude, longitude, tz = 32.2, -110.9, 'US/Arizona'
start = pd.Timestamp(datetime.date.today(), tz=tz)
end = start + pd.Timedelta(days=7)
irrad_vars = ['ghi', 'dni', 'dhi']
model = GFS()
raw_data = model.get_data(latitude, longitude, start, end)

Versions:
pvlib.version: 0.9.0
pandas.version: 1.3.2
python: 3.9.6
siphon.version: 0.9

Additional context
The above example is from the current documentation using the GFS model example. Also getting this error when attempting to use the HRRR model.

[kahemker]

It seems that the Net CDF Subset service is down. I have no idea who maintains this and where outages can be reported.

Start from this URL
https://thredds.ucar.edu/thredds/catalog/grib/NCEP/GFS/Global_0p5deg/latest.html?dataset=grib/NCEP/GFS/Global_0p5deg/GFS_Global_0p5deg_20211229_1800.grib2

Try to click "NetCDF Subset". See the 404 error from the following link: https://thredds.ucar.edu/thredds/ncss/grib/NCEP/GFS/Global_0p5deg/GFS_Global_0p5deg_20211229_1800.grib2/dataset.html

[kahemker]

Sounds like Thredds is back online. This issue can be closed