Can I sum SNODAS values for a given area?
SNODAS is a model output, so it is not recommended for use for quantitative water budget analysis. However, it is reasonable to sum values over a given area for a period of time, if, for example, you wanted to compare annual totals of snow water equivalent (SWE) for a given area. The solid precipitation variable (code 1025) can be used to calculate a running sum, with one caveat. The precipitation forcing data are separated into non-snow (L00) and snow (L01) components and both are provided as water equivalent. If the daily snow precipitation data are summed, the result can be treated as total snow water equivalent. However, it should be noted that when liquid precipitation falls and there is snow on the ground, this precipitation often increases the snow water equivalent in the short term and sometimes exits the snowpack at a later time.