General Comments:

The authors investigate a heavy precipitation event in meteorological, climatological and economical sense. It is shown that the chosen case was indeed considered extreme and had high impact therefore its analysis can be relevant for a wider audience and it also fits well into the scope of NHESS. The authors also included an experiment showing the effect of our warming climate on such extreme precipitation event, which help to put the case into perspective. The authors use valid methods to draw their conclusions. The paper consists many different aspects of the case, which have valuable information but also makes it a bit fragmented. I urge the authors to reconsider, if every part is really needed to support their conclusions and to try to shape it to be more coherent. Now it feels like different short analyses listed together.

Major Comments:

Section 2: I suggest this section to be restructured, even spitted into two. I would consider putting subsection 2.2 into the results section and mentioning COSMO-REA6 at the reanalysis section. In the 2.3 subsection it is not well explained why the authors used three different models. What is the added value in using so many models, could it not be done via one model? Also, the analysis done on WRF simulation could it not be done on the COSMO-CLM simulation, or the aerosol simulations with either COSMO or WRF? I also suggest to separate better the models description from the actual experiment set ups.

Section 3: This section should also be unified and simplified. I would suggest to move the methodology description in subsection 3.2 into the Method section and subsection 3.3 into 3.1. Subsection 3.4 consist some paragraphs which are describing the presented Table 1 and Figure 8, which feels unnecessary to me, I would suggest the authors to list more conclusions here. Subsection 3.5.2 also consists some methodology description, which should be moved to the Method section (PSI, cell tracking). Also it is not quite clear what is the contribution of the aerosol experiment to this case study, why is it a valuable part of the analysis.

Specific comments:

Page 2 Line 22 (last sentence) A bit vague.

Page 3 Line 3: I would not call Vb cyclones small-scale disturbances

Page 9 Line 217: How do you know that the spin-up was sufficient?

Page 12 Line 293: I would suggest to use “29 June 2017 HPE” instead just “29 June 2017” (not just here, but in the whole paper)

Page 12 Line 300: originated in the night from 28 to 29, would be clearer.

Page 22 Line 483: (Tab. 2, number 6 in Fig. 11)

Page 24 Line 518: “which exceeds the increase in precipitable water we find”, in where?

Page 26 Line 551: Which experiments fits better the observations? What are the conclusion related to this event?

Page 26 Line 567: “between Poland and northern Italy” strange wording

Page 26 Line 568: What does “this area” defines here? Not clear to me.

Page 28 Line 615: Is this a plane for further work?

Figure 7 Why are there so little lightning from the area of Berlin, where the precipitation has its peak?

General Comment

The paper presents the analysis of a heavy precipitation event affecting the Berlin metropolitan area on 29 June 2017 from different points of view. The analysis is very complete and the paper is well written.

Major comment

I do not have particular comments on the analyses or the results presented, which are very accurate and detailed. On the other hand, I have some comments on the presentation of the results. In my opinion, the most interesting parts of the paper are contained in Sections 3.2 (Lagrangian moisture source analysis), 3.6.1 (Conditional event attribution) and 3.6.2 (Role of Aerosols). Therefore, I would give more space to these parts, that, in the present version of the paper, have a marginal role. Contrarily, I would shorten the other Sections, which basically contain a description of the event. For example, I would include Section 3.3 (Observed lightning activity and accumulated precipitation) and 3.5 (Probability of exceedance and severity) in a new Section 3.1, which would contain the complete description of the event, from the synoptic scale to the impacts at the local scale. This, in my opinion, would improve the readability of the paper. The analyses that go beyond the simple description of the event may be included in subsequent Subsections (or in a new Section 4).

Minor and technical comments

Line 113: lightNings

Line 178: is the resolution of ERA5 25 x 25 km² or 31 x 31 km², as stated at line 150?

Line 230: corresponding approximately TO the peak…

Line 480: I do not understand why the 29 June 2017 event is the 29^th most severe event in the 1951-2021 period.

Line 486: The Ahr flooding in July-2021 (number 7 in Fig. 11). Should be number 9?

Line 488: due to the lack OF observations

Line 563: Rasmund II induced… Rasmund II or Rasmund?

Line 565: triggered several thousand convective cells... is “several thousand” correct?

Line 568: Lightning activity was especially active…repetition

Figure 2: what do the vertical lines in panel b represent?

Figure 12: Is this Figure referring only to the area surrounding Berlin, as written in the caption? If yes, what area? Panel b of Figure 1? Moreover, can you give more information on how data are divided into the two groups?