akrherz
commented
4 months ago dep-nexrad and to come up with correction factor for DEP-nexrad precip and temps.
One item I would caution in this space is that GHCN is generally 24 hour data observed at 7 AM, whereas at least DEP-nexrad is something close to US Central Midnight. There is a systematic bias between the two datasets given how a cold low at 7 AM can occupy two days. Here's a simple bias computation for the Des Moines ASOS by comparing the 6 Z cough midnight daily high and low vs a 24 hour computed at different times of the day:
Thankfully there is very little present day GHCN data taken in the afternoon, but some still exists and it was much more common a number of decades ago.
rogerlew
Hi Roger - would it be possible to make WEPP climate files from GHCNd daily precipitation and temperature values https://www1.ncdc.noaa.gov/pub/data/ghcn/daily/ These are the stations that is used to make CLIGEN PAR files and are at lower elevations.
I was thinking to compare this product with daymet, gridmet, prism, and dep-nexrad and to come up with correction factor for DEP-nexrad precip and temps. Previously, we did this at SNOTEL site but for this we can do the same at GHCNd locations.
ULMO python (https://ulmo.readthedocs.io/en/latest/api.html#module-ulmo.ncdc.ghcn_daily) under "NCDC Global Historical Climate Network (GHCN) Daily" has a way to download daily values of precipitation and temperature that we could use directly or we could download these directly from website.