Make flag for omitting P3 subgrid variability #1021
Description
We've been meaning to create a version of SCREAM which has cloud fraction of 0 or 1 and no subgrid variance of qc for a while now. This still isn't a high priority, but @mrnorman would like a flag to turn off subgrid_variance_scaling in the next month or two for MMF to use P3. The full task will also involve tweaking SHOC.