change multiyr average approach#589

Rick-Methot-NOAA merged 2 commits intomainnmfs-ost/ss3-source-code:mainfrom

586-feature-10+-multiyear-average-f_std_scalingnmfs-ost/ss3-source-code:586-feature-10+-multiyear-average-f_std_scalingCopy head branch name to clipboard