FAQ: Can I initialize the SCM using initial conditions or forecasts from the Unified Forecast System?

Can I initialize the SCM using initial conditions or forecasts from the Unified Forecast System?

It is possible to initialize the SCM using UFS initial conditions, although advective forcing is currently a work-in-progress, and will be included in a future release. To create initial conditions, please read section 5.5 of the SCM User and Technical Guide. 

Briefly, one needs to have access to the UFS initial conditions data and use a script in the repository called UFS_IC_generator.py. This script takes the following pieces of information as arguments:

1. The longitude/latitude OR the FV3 tile and i,j indices of the desired point
2. The directory containing the initial conditions
3. The directory containing the FV3 grid information
4. The date corresponding to the initial conditions
5. A string to use as a name for the SCM case file that is generated

Using this information, the script reads the appropriate data and produces a case input date file in the netCDF format that the SCM expects. Note that optional arguments to the script allow generation of initial conditions for use with the Noah or NoahMP LSMs and to be able to use initial conditions generated from the current and older versions of the “chgres” program that was used to output the initial condition data files.

In addition to generating a case input data file, one would also need to create a case configuration namelist (in scm/etc/case_config) with appropriate values, including setting the variable model_ics to True.