Evapotranspiration

ET is also very sensitive to elevation. However, the function is rather com­plex. The lower temperatures will reduce ET with elevation. However, the wind speed may be higher which will increase ET. If there is more rainfall at higher elevations, or if the humidity is higher, then this will also act to reduce ET. And, solar radiation may be more intense at higher elevations.

There is currently no means to automatically adjust ET with elevation. So, if you need to consider ET versus elevation, then you will have to generate either a spatially varying ET grid, or local time series of ET and apply these in different elevation zones.

Overall, if your winter evapotranspiration is too high, you will underestimate your snow pack accumulation.