Automated quality control procedure for the "water equivalent of snow on the ground' measurement

Abstract

Snow water equivalent (SWE) has been measured daily in the USA since 1952, whenever snow depth is 2 in. (5 cm) or greater. An automated quality control procedure for these data is developed here, which checks daily SWE values for common data entry errors, values beyond reasonable limits, and consistency with daily precipitation and estimated melt. Potential effects of drifting in high winds and of the intrinsic microscale variability of SWE are also considered. An SWE measurement is declared suspicious if a sufficient discrepancy is found with respect to the expected SWE. Data values fagged as potential errors are checked manually. Results of applying the procedure to available SWE data from the northeastern US are also summarized. -Authors