This study analyzed the impact factors in an extreme precipitation event that occurred during July 2023 in Beijing, based on the Weather Research and Forecasting (WRF) model. Several experiments were selected to assess the impacts of topography and land use, with examining the causes of the event and the related mechanisms. It concludes that topographical features caused the uplift of air masses in the mountainous regions leading to significant enhancement of the convective intensity over Beijing and precipitation for a prolonged duration. The presence of urban surfaces contributed to reductions in the latent heat flux and wind speed, resulting in decreased energy transfer to the southwestern mountainous regions via easterly winds.

This study is interesting and the manuscript is well written. There are some issues that could be addressed to improve the manuscript quality.

Introduction: This part is generally coherent and logical, but there are some expression issues that need improvement.

Lines 57-59: The last sentence is related to the effect of surface roughness induced by cities. Therefore, it better remove this to the paragraph of introducing urbanization.

Line 79: … another key factors …., since the authors have pointed out topography as one of the most important factors.

Lines 82-83: Delete “which significantly increases the surface roughness”. Urban heat island can cause convergence and upward lifting in the lower atmosphere, but is not the cause of surface roughness.

Lines 87: Delete “modifying”.

Lines 102-103: This sentence introduces the research area, but the expression is not coherent and needs to be revised.

Experimental Design:

The WRF simulation is carried out on 49 vertical layers and the upper boundary was set as 50 hPa. Is there any evidence or literature supported this setting?

Results:

Line 225: Is “EP” shorted for “extreme precipition”? This abbreviation is only used once and need be changed.

The authors state that using CMORPH data to validate the simulation results was highly reasonable, although it is an indirect observation data. The average precipitation intensity obtained from the simulations was compared with the precipitation intensity of CMORPH. Therefore, it suggests presenting the results of the statistics of MAE, RMSE and R, or at least listing them in a table.

For the physical mechanism of this precipitation event, the authors can focus on the water vapor transport, especially the differences in water vapor budget at each of the boundary.

Discussion:

This study involved the main physics schemes based on the model configurations listed in Table 1. It is recommended to analyze the limitations of this study, or the impacts of different physics schemes.