I’d like to run some WRF forecasts for dates on which there were large errors in the shortwave (SW) radiation from reanalysis data. To do this, I need to get forecast data from a global model.
The GFS global model forecast data are archived here: https://www.ncdc.noaa.gov/data-access/model-data/model-datasets/global-forcast-system-gfs
To request archived data, click on the HAS link for the data you want – I’ll use the 1º GFS data, as it goes back further.
The case study WRF forecasts will start at 12UTC, so I’ll select that cycle. For each case study date, request data for that day and the five previous days using the Start Date and End Date fields. Skip file selection, as it’s one file per day (no choice). Enter your email address and click “Proceed With”. You should get an “Order Submitted” page not. If not, go back, click “Reset From”, and try again.
When the data are ready for download (~20 minutes), you will get an email with a link to the download directory. I download them using curl with the ftp address:
curl -O ftp://ftp.ncdc.noaa.gov/pub/has/model/HAS010940358/gfs_3_2007062412.tar
Each day comes as a tar file, around 1GB in size for grb2, 1.5GB for grb. The tar file contains a grib file for every 3 hours, from analysis to +384h (16 days!). Each grib file contains surface and pressure level data. There doesn’t seem to be a way to request a subset of this data (I only want 5 days forecast data).