The manuscript "Seasonal Snow-Atmosphere Modeling: Let's do it" by Reynolds et al. introduces a new model setup based on the coupling of the HICAR with FSM2trans to resolve snow depth and snow-atmosphere interaction more effectively. For model performance demonstration, the authors applied the model setup to a case in the Swiss Alps and validated the model output with survey data from LiDAR flights. They found improvements in the model performance for surface temperature, blowing snow sublimation, and snow depth after coupling the snow component of FSM2trans (FSM2oshd) and using the ISHMAEL microphysics scheme that discriminates three types of ice states. 

The well-written study may contribute to scientific advancement in snow modeling and other applications. Therefore, it may interest a broad range of scientists in various disciplines. However, a few more general points could be addressed and discussed more deeply in the manuscript.

When referring to figures, sometimes "Fig." and sometimes "Figure" are used. A uniform referencing system would be better.

Section 2.1: This section could be supported with a schematic diagram that outlines the model setup.

Section 2.2: Which of the redistribution processes was calculated first?

L 128: How sensitive is the model to different amounts of iterations?

Section 2.4: How sensitive is the model to the amount of snow layers? Does the top layer represent the surface that interacts with the atmosphere?

L. 170: There is a (TODO: HERE)?

L. 205: Which criteria are used for partitioning precipitation into snowfall and rainfall? How is the rain-snow slope line defined?

Section 3.1.1: What contributes most to the advection of snow particles and snowfall pattern during the event (wind aloft, above the ridge, or the updraft on the downwind slopes)?

Section 3.1.2: How much do the two discussed redistribution processes (wind-driven or gravitational redistribution) individually contribute to total redistribution? Can you give an estimate?

L. 333: It would be good if there were a brief statement of model performance in terms of meteorological variables earlier in the manuscript.

L. 355: "5" is "Figure 5"?

L.359: "The following paragraph ..." could be a new paragraph.

L. 363: Is the warm bias due to the too low albedo in high elevations?

How is snow albedo parameterized, and which values are assumed for fresh and accumulated snow?

L. 375: "4" is Figure 4"?

L. 435: Are the differences in the blowing snow sublimation percentage of snowfall due to differences in snowfall or the rate of sublimated snow?

This is a review of "Seasonal Snow-Atmosphere Modeling: Let’s do it”. Overall this is generally a quite well written and readable manuscript. The science is really exciting and at the forefront of the field.

My main suggestion is that the authors very clearly articulate the science questions that motivate this study. The introduction does a good job of setting up the research gaps, but I found many of the sections came at me a bit out of the blue. For example, I would really like to see clear science questions that establish the need for Morrison v. ISHMAEL, and specific method which the authors had a priori anticipated working well in this domain.

Some of the model decisions are behind in-prep manuscripts, which makes it a bit hard to follow some of the modelling decisions. For example, why the spatial resolutions were chosen.  Indeed, it is pretty obvious to those of us who do this kind of modelling, but I think it would help readability if these model decisions were better articulated, the sensitive of the results to them, and for them to be tied to the underlying research questions. If this is tightened up, it should be a very easy-to-follow manuscript.

The domain has very few (none?) trees. Realizing it is a bit out of scope, I am very curious to know what the authors think of applying these methods to more forested catchments that have complex interactions of canopy-wind in the downslope regions.

w/c = Word choice

L20 Exposed to what?

L21 is it really a discontinuity though? The derivative remains well defined. I think this would be better restated as "sharp gradient" or similar

L23 "modified" w/c. Modified feels like a model input term

L34 space between amount an dunit – 100m -> 100 m. Fix throughout

L34 "at elevations" - "at a height above the surface of" might be more clear to match the language on L41

L57 "modern" -> contemporary?

L58 "troubling" w/c

L65 "These conditions have been followed by the earlier studies" what conditions are these and how can they be followed by an earlier study? 

L66 " This is due to" unclear what this is in reference to

L67 horizontal and vertical resolutions?

L67 "One exception to this " what is this?

L67+ There is a lot of "this" throughout the section, which makes it difficult to follow. Generally I can infer what "this" is in reference to, but it would be best to explicitly state it to ease readability.

L72 "Caveat aside" which caveat is this in reference to?

L74 "adopting this strategy" this == intermediate complexity atmospheric models? 

L85 what are the scientific questions, specifically?

L90 Later in the MS I found the mix of FSM2trans (e.g. fig 11), HICARsnow, NoahMP, a bit confusing. L 103 notes the name depends on the coupling strategy. I think a small table or a very clear description of all the comparisons would help readability

L93 define `oshd` ?

L96 static lib, are you meaning a `.a` ? This is very specific — do you mean this to preclude using a dynamic lib?

L109 FSM2 has a soil routine. How are frozen soils + the ground heatflux coupled into this? Or is this fully disabled in this configuration

L128 Is there an opportunity to use a dynamic iteration based on an error term versus a fixed iteration count ? 

L125 “image” is not clear. I have a vague recollection this is maybe a iSNOBAL term? For the raster? Can you please clarity.

L170 fix TODO: HERE

L171 can you list, even briefly the details? Difficult to tell with an in-prep manuscript (but I do understand)

L235 Maybe it is just the layout, but it seems that the text goes from citing Fig 2 to Fig 6&7. My recommendation would be number the figures in the order they appear. As is, I’m finding it difficult to find the text that references a specific figure

L 275 Figure 7: What are the purple contours in the 2nd row? I don’t see them in the legend. I like this plot though.

L331 How is the surface roughness interaction with HICAR modelled?

L359 “The following paragraph” — suggest you start a new paragraph

L361 how big is “slight”?

L414 Do you think this excessive cooling impact ablation rates? I had originally read this as a FSM2 characteristic, but rereading the text I’m uncertain if it is actually NOAHMP. Please tighten this up a bit

L443 these tradeoffs should be clearly noted in the methodology