In this paper, the seasonal evolution of a mountain snowpack’s physical state is analyzed over a 72-year period by means of a physics-based snowpack model to assess long-term changes in its capacity to buffer runoff from liquid water input. The manuscript is well-written and I only have a few minor comments.

Abstract:

- 12: I recommend to mention the model that is used already here by name.

Introduction:

- 67 - 69: „Broad regional-scale“: can you specify what size you mean with this? Is your „large Columbia headwaters basin“ of this size, or larger/smaller? Does „... not only computationally impractical but may obscure the importance of transient and localized processes“ also apply to the latter, or not? Please clarify.

Methods:

- 78: What Do you mean with „undeveloped“ forest?

- 93: Maybe better begin new sentence with „With this resolution …“.

- 94: Maybe better insert „snow allocation and surface hydrology model“.

- 95: The Swiss meteo data processing tool’s name is „MeteoIO“.

- 125: Which values did you obtain for the irreducible water saturation?

Results:

- 226/Figure 5: Here you mean „Late accumulation period“, right? Better replace „Early Spring“.

- 230: Better replace „fall“ with the term you defined earlier (159 - 161): „Early Accumulation“.

- 231: „Early Accumulation“ should be „Late Accuumulation“ here, right? And the dates, as defined earlier: March 9 to April 17. Better stay consistent (see 159 - 161).

Appendix:

- Figure A1: Add units to (a) and (b).

- 503: Refer to method mentioned earlier (regression, Pan et al., 2003), or insert again here so that the origin of the factor becomes clear.

Please see the attached file outlining my recommendations.