This study analyzed the impact of urban areas on thunderstorm organization processes and CG flash activity through ground observations and numerical simulations. City size may be an important factor affecting thunderstorm processes. In addition, the building density may also alter the organization process of thunderstorms. Overall, I believe that the research presented in this article has some innovation and the conclusions are also very interesting. The organization and writing of this article need improvement, and I would like to suggest significant revisions to this paper. 

1. The author has failed to define a thunderstorm that is grounded in radar reflectivity or other pertinent parameters, leaving the reader without a clear understanding of the term's scientific context.

2. This article highlights a specific thunderstorm process that exhibited a barrier effect through both observations and simulations. However, to strengthen the argument that this phenomenon is widespread or common, the author should provide additional cases or statistical results to support their findings.

3. Has Figure 3 exclusively analyzed CG events that occurred during the summer? If so, please include a relevant description in the caption of Figure 3. Furthermore, the author should provide a clear description of the data in the data section.

4. Please add the symbolization of the red line in Figure 8.

Overall Review:

This manuscript examines lightning location data, along with a numerical model, which indicates that urban morphology in Beijing's metropolitan area influences where lightning strikes—a phenomenon known as the urban barrier effect. By integrating lightning data with a model that considers building size and height, the manuscript presents interesting case studies demonstrating how large cities can influence weather conditions, thus affecting lightning patterns. However, the manuscript lacks sufficient clarity in its data presentation, methodological approach and structural hierarchy, causing confusion for readers. After addressing my primary comments, I recommend publishing this manuscript in ACP.

Major comments:

1. Figure 1 provides an overview of the study area, encompassing the boundaries and spatial locations of China, Beijing-Tianjin-Hebei region, and Beijing. However, as the focus of this study is the urban area of Beijing, Figure 1 lacks a sufficiently detailed depiction. While Figure 2 offers some insight, I believe it is crucial to supplement Figure 1 with more specific information about the urban area of Beijing.

1. The observation section of this article has obtained many interesting statistical results based on compact high rise, compact mid rise, compact low rise, open high rise, open mid rise, and open low rise. However, sensitivity tests were conducted in the simulation section based on compact rise and open rise, and the test results to some extent explained the mechanism of the influence of urban morphology on the process of thunderstorm organization. What are the standards used for the classification of urban morphology in the observation and simulation sections? Is it consistent? Please provide a detailed explanation.

1. Weather Research and Forecasting (WRF) serves as a vital tool in this paper for analyzing the mechanisms of how urban morphology impacts the thunderstorm process. However, the author's introduction to WRF lacks sufficient detail, especially regarding the WRF model coupled with the urban canopy, which poses challenges for researchers unfamiliar with this system. The author should provide a more comprehensive explanation of WRF and the simulation scheme to enhance the readability of the paper and ensure the reproducibility of the experimental results.

Minor comments:

P1Line15: "mega cities", should be "megacities"

P1Line18: "weakening" should be preceded by "the"

P1Line30: "population" should be revised as "populations"

P2Line45: "that" in "....despite that....." should be deleted

P2Line49: "millions"  ->  "million"

P2Line61: "built up"  ->  "built-up"

P2Line67: What does "BJ" mean? Is Beijing an abbreviation?

P2Line67: "sof" may be "of"

P4Line96: "refers"  ->  "refer"

P6Line118: deleted "the" in "....the Table 2....."

P6Line125: deleted "the" in "....the Table 3....."

P8Line141: "an average and maximum densities"  ->  "an average and maximum density"

P8Line145: "exists  a potential" has one more space

P9Line146: "by high" should be added "a"

P12Line203: "during "0713" case" should be added "the"

P18Line305: "all types of building" should be "all types of buildings"