Convection Parametrization and Multi-Nesting Dependence of a Heavy Rainfall Event over Namibia with Weather Research and Forecasting (WRF) Model

Round 1

Reviewer 1 Report

The article entitled "Convection parametrization and multi-nesting dependence of a heavy rainfall event over Namibia with Weather Research and Forecasting (WRF) model" aimed to Ninvestigate the effects of using multi-nesting and a convection scheme in the simulation of an event of heavy rain in northwestern Kunene, Namibia.

The article presents a clear and consistent language with scientific writing, addresses strong references to the consulted theme, which gives theoretical basis to the content.
The methods and techniques employed are clear and relevant. The objective is achieved in a striking and highly explanatory way.
However, the authors need to make clear in their final considerations the strengths and limitations of the research. This is necessary to highlight the importance and scientific weight of the methodology explored.

I recommend accepting.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Reviewer Comments:

The authors of this manuscript are evaluating a case study of a heavy precipitation event over Namibia using multiple configurations of the WRF-ARW atmospheric model. WRF-ARW is a well-established and heavily cited regional atmospheric model, and is a good choice for this analysis. The authors consider the impacts of both convective parameterization and domain configuration (i.e. nesting) on model performance and the realism of model precipitation structures. This analysis is an important contribution to the regional modeling field, as it considers the limitations of convective parameterization and other factors that can impact model performance.

The analysis shown in the manuscript is also valuable because it considers the utility of regional modeling in the developing world, and this can be valuable both for operational meteorology as well as research into extreme events and climate change impacts assessment. I do find some weaknesses in the analysis performed in this manuscript.

I am recommending this manuscript be accepted with major revisions, and I am suggesting several additions to the paper that will strengthen the arguments made by the authors.

Major Comments:

1) In Section 2 (lines 102-117), the manuscript describes literature on several convective parameterizations and its performance in the model study region. This is important; however, the authors do not discuss any literature on the Tiedke cumulus scheme and why it was selected here. This is only briefly mentioned in section 5 (conclusions). Could the authors justify their selection of the Tiedke scheme over other convective schemes?

2) In section 4.2 (lines 237-239), the authors describe that they selected a point in the model simulation where greater rainfall was simulated, and this was compared to the Khorixas station. I realize that at times, CPMs will tend to misplace the position of precipitation (as I note later on in my minor comments). Could the authors justify how this point was selected, as it seems sort of arbitrary. The authors may also want to consider analyzing multiple points in the simulation, as this might be more objective. I am concerned that one carefully chosen point in the model simulation can be used to justify anything that the authors want to prove.

Minor Comments:

Lines 87-92: This is a good commentary on the benefits of CPM models.

Line 313: There is a missing parenthesis in the reference to Figure 7a.

Lines 321-324: This is an important point about CPM models.

Lines 380-384: This comment on the Tiedke scheme is definitely relevant. Could the authors provide details on this earlier in the manuscript (see my major comments)?

Figure 2: Text labeling the lat/lon lines is too small. Please redo this figure to make this more legible.

Figure 3: As noted in Figure 2, same issue with lat/lon text.

Figure 7: As noted in Figure 2, same issue with lat/lon text.

Figure 8: As noted in Figure 2, same issue with lat/lon text.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

This manuscript evaluates the effect of permitting convection and multi nesting in the simulation of an extreme rainfall event in Namibia. The authors found that permitting convection in simulation results in lower rainfall intensity. Multi nesting results in slightly different extreme rainfall locations. Overall, the study and findings are interesting and the methodologies are robust. The manuscript fits the scope of the journal Climate. However, my major concerns are that the results/discussion lacks the attribution of the findings.

#1 Please briefly explain why the model developer recommends the parent-child domain nesting ratio to be 3 for ideal simulation? How intermediate nesting (multi nesting) overcomes that limitation?    

#2 I suggest authors compare climatic/meteorological conditions during the heavy precipitation (3. Event Description: L141-178) from different products including Global Forecast System (GFS).

# I suggest authors compare the geography of the simulated and observed heavy rainfall locations

#4 L91-92 confusing sentence. It seems like the sentence is misplaced.

#5 Label Figure 1 color bar (contours in m?)

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

The manuscript is improved after the revision. I have no further comments on the manuscript.