Snotel gives reported snow depth at precise locations.
Windy shows forecast snow depth by ECMWF model.
Getting discrepancies between this data is not abnormal.
First the resolution of this global model is 9km (5.6M). So in mountains it is not very accurate, also because the orography model ( i.e. the vertical terrain resolution) used by the weather model is quite coarse too.
Then, after snowfalls, snow layer compacts and its density increases. This factor is difficult to estimate. And finally snow partly melts.
The Snow depth map is interesting to compare a region with another one or to get an idea about the snow depth in the following days. But it's not a way to know the precise snow depth at a location.