Overview:

The manuscript titled “A quantitative module of avalanche hazard—comparing forecaster assessments of storm and persistent slab avalanche problems with information derived from distributed snowpack simulations” sets out to improve avalanche forecasting quality through the development of an additional toolset and analyzes the effectiveness of this toolset in this paper. The authors leverage recent scaling developments in the utilization of the SNOWPACK model to produce spatially distributed snow cover outputs over ten winter seasons for the Glacier National Park, Canada. They then post-process this data to produce numerical predictions of the characteristics of storm snow and persistent avalanche problems and compare those results against the timeseries of daily human hazard assessments. Their comparison is extensive and thorough, both evaluating broad trends and specific event day-to-day evolutions of avalanche problems. They describe their methods clearly despite the relative complexity required in post processing and inter-comparison of their datasets. The results and discussion clearly establish where their work fits within the current sphere of research and the contribution their methods offer to the snow and avalanche science community.

I do not have any major issues with this manuscript and feel that it is of very high quality. The largest question raised is whether or not they considered comparing their two hazard assessments (simulated and human) against observed avalanche records? I realize that the additional effort is probably outside the scope of the current project and that there are known limitations to observational records but also believe that their specific domain - Glacier National Park, Canada - has potentially one of the most complete and thorough records available due to the high level of professional avalanche activity in the terrain in and around the park. These records, and additionally utilizing the Avalanche Hazard Index (Schaerer, 1989), could provide a relative “truth” in the avalanche hazard characteristics being compared. I would appreciate a response to my question but do not feel that this further analysis is required for publication given the robustness of the work presented.

Specific technical corrections and comments:

Line 100 – use of word “over” is confusing within the discussion of the ordinal likelihood of avalanches scale, simply remove to clarify

Line 106 – use of word “over” is confusing within the discussion of the ordinal North American Public Avalanche Danger Scale, simply remove to clarify

Line 119 – “layers that were exposed to the snow surface” is confusing, perhaps adjust simply to “layers that were the exposed snow surface”

Line 120 – “represent rain events that form a crust” implies that rain is the only way surface crusts form and the date tags probably include additional crust formation events. Perhaps something like: “represent crust formation events at the snow surface such as rain or insolation-driven melting.”

Line 180 – It seems as though the likelihood of avalanches should be represented by the layer with the highest p_unstable value or an average for that profile rather than the lowest?

Figure 5g – Color and interquartile range of air temperature line is the same as p_unstable in plots 5c-5f and, therefore, is slightly confusing. Consider changing it to dashed or a different color to differentiate it.

Figure 5h – Color of median high of new snow is the same as storm slab instabilities in plots 5d and 5f, and, therefore, is slightly confusing. Consider changing the color to differentiate it.

Figure 6 – It appears but is not explicitly described that assessed values are solid and modelled are hatched. Perhaps mention this in the figure description or add a legend.

Line 299 – “increased strongly” doesn’t make sense in reference to the simulated depth of the weak layer, perhaps remove “strongly” or change wording to “increased substantially”

Line 304 – “short and moderate peaks of modeled instability” is confusing since “moderate” is not defined within the spectrum of modeled instability

Line 331 – “as” is meant to be “was”

Figure 8c & 8d – “Turn-on” and “Turn-off” are confusing category names and I am interpreting it them as if the avalanche problem was assessed (“Yes”/“No”) or added/removed?

Line 359 – “is unstable” should be “are unstable”

Line 361-363 – You mention that deeper splits show a generally higher hazard rating associated with storm snow problems than persistent problems. Is this due to the relative frequency of lower hazard ratings associated persistent problems (aka “spicy moderate” or existing for weeks) vs. the short-term spiking hazard commonly found with storm snow problems (quick to rise and quick to fall)? If so, I believe it is worth clarifying the relative temporal effects of both types of problems because your results discussion seems to say that the model simply pairs lower hazard with persistent problems.

Line 380-381 – Delete sentence since it seems you are submitting the manuscript for publication in a peer-reviewed journal and I hope you’ve taken those additional research steps.

Line 423-425 – Very concise distillation of the effectiveness of your model – nice job.

Line 444-445 – How do forecaster’s removal of reported persistent problems appear arbitrary? That is a big statement to make given the multitude of factors forecasters must balance to make that call.

Line 545 – Understanding the truth of avalanche hazard is infinitely complex. Has your team considered comparing your results with observed avalanche activity to quantify the accuracy of avalanche depths/size and loosely distribution (despite the inherent bias in physically observed avalanche records)? I wonder if this could help clarify a relative truth especially when the simulated and reported hazards differ?

Final Thoughts:

I reiterate that with minor updates this paper will be a valuable addition to the avalanche forecasting and snow science communities.

The manuscript titled "A quantitative module of avalanche hazard—comparing forecaster assessments of storm and persistent slab avalanche problems with information derived from distributed snowpack simulations" presents a well-executed study aimed at enhancing avalanche forecasting by integrating numerical snowpack simulations with human judgment. The study introduces a spatial approach to extracting the characteristics of storm and persistent slab avalanche problems from distributed snowpack simulations, tracing individual snowpack layers over time and space. This approach enables the calculation of spatial distributions of avalanche problem characteristics and presents the data in familiar hazard chart formats aligned with the (CMAH).

The study leverages snow cover data spanning ten winter seasons from Glacier National Park, Canada, to examine the agreement between snow cover simulations and human assessments for persistent and storm slab avalanche problems. The comparison is thorough, addressing both seasonal trends and day-to-day evaluations. The authors clearly describe their methods, which are up-to-date and well-suited to the study’s objectives. This work aligns well with recent advancements aimed at integrating snowpack modelling more closely with operational forecasting workflows.

The applied methods and developed approaches are of high quality and contribute significantly to the goal of further integrating snow cover modelling results into avalanche forecasting workflows. The comparison between modelling results and human assessments provides a valuable foundation and insights for future applications.

Minor Corrections and Comments:

Line 174: I noticed a small typo in the phrase 'characteristics avalanche problem type'; I assume it should be ' characteristic avalanche problem type'? Additionally, I concur with the comment by Frank Techel that, for clarity, it would be beneficial to consistently use the term p_unstable when referring to the model predictor. This distinction will help avoid (my)  confusion, when differentiating it from human assessments (e.g., Line 174 and other locations).

Line 175 – 178 & 180 - 181: To me, it is unclear how the depth of the identified layer differs from the depth of the deepest unstable layer. To my understanding, these two are the same. Consider revising for more clarity, otherwise I would be interested in a reply to clarify this distinction.

Line 178 & 181: I assume this is a typo, and p_unstable ≤ 0.77 should instead read p_unstable ≥ 0.77.

Line 186: I do not understand the term 'spatial distribution' as it relates to Figure 4, as I don't see any spatial component represented in the figure. Consider revising this term for greater clarity.

Figure 5: For clarity, it would be helpful to choose different colours for air temperature and HN24, as the current colours are very similar to those used for p_unstable and avalanche problems in the upper panels. Additionally, I assume that air temperature and HN24 are based on modelled data rather than measurements? It might be beneficial to add a small comment on this for clarity.

Figure 6: It took multiple views to understand that the hashed bars represent modelled data and the full-colour bars represent assessed data. To improve clarity, consider explicitly stating this in the figure caption for easier understanding."

Line 380: Remove sentence – you are already submitting to a peer-reviewed journal.

Conclusion:

I do not have any major issues with this manuscript; the research is solid, and the conclusions are well-supported by the data. My comments are minor in nature. Overall, I recommend this manuscript for publication after these minor revisions are addressed.