Summary:

The study uses Faranda’s attribution technique to assess the impact of climate change on four extratropical and tropical storms.  The stated goal is to assess the effect of climate change on airport operations, but aside from brief and general statements in the introduction about how air traffic is affected by storms, little connection is made between the effects of climate change and airport opertaions.  When reading the abstract and title I was expecting a more detailed and quantitative analysis of how the impacts on airport and flight operations have been affected by climate change.  In the summary section, the authors state: “In summary, our findings demonstrate that Eunice-like storms are becoming more severe in the current climate, with significant implications for transportation systems and public safety.”  Except for vague allusions this has not at all been addressed in the manuscript.  Some suggestions how to address this follow below, and my recommendation is major revisions.

General comments:

1. The link between the impacts  of the effects of climate change and airport operations are superficial and sometimes misleading (e.g., stronger headwind actually improves airplane performance; the authors also suggest an increased risk due to increased tailwinds, which is not likely a big impact because tailwind operations are easily and commonly avoided); while wind shear in downbursts is dangerous, in extratropical cyclones wind shear typically means that the planes take off into the shear, which improves climb performance (likewise, descending into wind shear acts to increase the headwind, so it is not inherently dangerous).  So, a much more nuanced analysis is needed when considering the impacts of ETCs on aircraft operations. (I’m not arguing that stronger winds don’t cause disruptions, but the current argument in the manuscript is imprecise.)
   
   
   
   My recommendation is that either the “spin” of the paper is adjusted, away from airport operations, and instead putting more emphasis on how the weather systems were affected by climate change.  Alternatively, a much more detailed analysis about how climate change actually affected air travel would be needed: Given the increases of turbulence/wind speed, how many more delays happened due to climate change?  What are the costs?  Wouldn’t this be the questions that stakeholders would be interested in?
2. Throughout the manuscript, the authors use wind shear (which should have units of 1/s rather than m/s) when I think they mean "bulk wind difference" (which has the unit of m/s).

Specific comments:

1. Line 35: The impact of wind shear on aircraft performance is too vague.
2. Line 77: The development or presence of frontal zones?
3. Line 92: So you are considering the temporal minimum?  When the ETC was the most intense?
4. Line 97: 35-year periods
5. Line 141: Either use e.g., in front of the Volonte reference, or cite the original study by Browning where the phenomenon is introduced
6. Line 167: Not sure what you mean by pressure lines becoming narrower.  Pressure gradient increasing?
7. Line 174: Not sure about the tail winds—these are easily avoided by choosing the appropriate runway.
8. Line 178: Shear has the units s-1—you probably mean wind difference?
9. Line 210, 225: precipitation (no plural)
10. Line 237: “Very extremely high” is a little excessive.  Just state that there was an anomaly of +7 K.
11. Line 244: Suggest starting a new paragraph here.
12. Line 248, 251: Wind speed gradients have the unit of s-1.
13. Line 251, 254: Wind shear (commonly used in its singular form); also, incorrect units.
14. Line 255: Not sure why turbulence suggests frontogenesis; please provide additional justification, or omit.
15. Line 258: Check units of the wind speed gradients.

Review egusphere-2025-1219

The impact of climate change on the intensity of mid-latitude cyclones, and their effect on airport operations, is analysed in this manuscript. Focussing on four recent case studies, the authors use a storm analogue method to compare the storms to four similar ones found in an earlier time period. As the earlier time period has been less impacted by climate change, the differences in storm intensity are attributed to the effects of climate change. In most of the cases, human-induced climate change is found to intensify the storms, in either (or both) their wind speeds and precipitation. The authors highlight the impacts these storms had on airport operations and discuss how these may change as the climate continues to change. 

The paper is well written, the analyses appropriate for the stated aims, and the conclusions supported by the evidence presented. I think the manuscript will be of interest to the readers of WCD and I believe the manuscript will be suitable for publication following a minor revision. I have some comments that I would appreciate the authors’ thoughts on before I recommend the article be ready for publication. 

Mains comments:

1. This first comment relates to the analogue method.

As I understand it, the analogue method only considers the time of maximum intensity when looking for similar cyclones in the earlier period. I wonder how different the analogues would be (and therefore also the results) if you took into account the cyclone development. In terms of impacts, particularly for precipitation, the development period of the cyclone may matter more in terms of overall similarity than only the time of maximum intensity. I assume it should not be too difficult to look for analogues at various times before maximum intensity to see if the results are sensitive to this. Finding analogues that remained similar throughout their lifecycle may find cyclones that are more representative of the cyclones from the current period.

2. This comment relates to the modes of variability considered.

When accounting for low frequency variability you consider ENSO, the AMO and PDO indices. I was surprised you did not include the NAO as this is well known to greatly impact both the frequency and intensity of extratropical cyclones (granted for the North Atlantic/Europe primarily). Have you tested whether including the NAO in your assessment of natural variability changes your results? Some discussion relating to this is needed regardless. 

Minor comments:

L26: How many days/weeks is 165000 minutes? Might be useful for the reader to include that here.

L25-33: It might be useful to add context to this paragraph. E.g. why is it of importance. 

L61: you consider only ground level conditions impacting take-off and landing, could higher level (but still in the lower atmosphere) also prevent take-off and landing?

L67: Do you have any comments about the resolution of ERA5 when considering airport impacts? Many processes that are relevant may not be well represented in ERA5. 

L124: as mentioned earlier I would argue the NAO is more important in the North Atlantic. 

Conclusions: Do you have any thoughts on why climate change is making storms more intense? It would be good to add some discussion here detailing your thoughts. 

Technical corrections:

L59: since —> as 

L154: “Results by comparing..” I am not sure that this makes sense. 

L157: cyclone eye —> cyclone centre

L236: “very extremely high” do not need very and extremely. (And L237).