Temperature range defined separation of rain and snow in Canopy.cc
As of commit 574, it is possible to define a temperature range over which the separation between rain and snow is linearly changing, instead of a fixed threshold.
In Canopy.cc, this threshold is also used, but I don't know enough about Canopy.cc to make the appropriate changes in case someone wants to work with the temperature range instead of a fixed threshold.
The issue is not so important, though, as the model is still expected to work and produce sensible results as the fixed threshold will always be in the middle of the range, but the issue may need to be addressed in the future.