Dear authors,

please find my review of the manuscript attaches as a pdf.

General Comments:

This manuscript is devoted to studying Saharan warm air intrusions in the Western Mediterranean during a historical period (1959-2022), emphasising not only their identification methodology (considering different intrusion types according to their location), and the resulting creation of a catalogue of events, but also the assessment of their impacts on air temperature extremes and the analysis of the large-scale atmospheric driving mechanisms, namely upper-tropospheric anomalies over North Africa. Overall, the topic of research is within the scope of WCD and pertinent under a climate change context and increasing occurrence of temperature extreme events. The datasets used (daily tropospheric variables obtained from the ERA5 reanalysis) are adequate for the purposes of the study, whereas the methodology to identify the different intrusion types provides some novelty. The methodological approach for the detection of Sahara air intrusions in Western Europe is simple and effective, with low computational costs. The results are scientifically sounding, based on sufficient evidence provided by the authors and are in line with previous research outcomes. Generally, the figures are of good quality and the length of the manuscript is adequate. Therefore, I recommend the publication of the manuscript after some revisions that are outlined below in the specific comments.

Specific Comments:

Abstract: You mention four ITs. However, depending on the season, different numbers are obtained and considered in the manuscript. Please revise.

Section 1: There is some unnecessary repetition of citations to previous studies (e.g., Sousa et al. 2019), while other relevant references are still missing (e.g., 10.3402/tellusa.v67.26032, among others). I suggest a more in-depth literature review, as many previous studies have already linked temperature extremes in the Western Mediterranean to atmospheric large-scale mechanisms and anomalies. This is particularly pertinent to corroborate the present study results and provide a good state-of-the-art on this topic of research, giving sufficient credit to other preceding studies. 

Ln 50-65: I would avoid bullet-point lists. Providing more compact text is commonly preferable in scientific manuscripts.

Ln 54: please avoid using "etc". Be more specific.

Section 2: The dataset selected for the analysis was ERA5. Although this choice is adequate for the goals of the study, it should be complemented with weather station data (e.g., from ECA&D), as reanalyses commonly present important biases in near-surface weather conditions, particularly in capturing small-scale spatial variability and local weather/climate patterns. The use of maximum temperatures (TX) recorded at local weather stations would help validate the occurrence of temperature extremes. Hence, I suggest the incorporation of some weather station data to confirm and better quantify the intensity of the extreme events. From my point of view, this is an important limitation on the robustness of the study, though it is not expected a major impact on the results.

Section 3:

- Please do not use physical units in italic font.

- Rd is the "dry air gas constant".

- Cp should be cp (lowercase C).

Figure 1: the dashed black box within the Western Mediterranean box is not sufficiently explained in both the caption and text. It seems that the selected day for Fig. 1 does not fulfil the corresponding area requirement.

Ln 101: "rolling" or "moving"?

Ln 103 & 104: "red shaped" or "orange"?

Figure 2 shows a strong positive correlation between both variables. The same is clear in Figure 4. This hints at the high level of redundancy (colinearity) between variables and the information they bring to the analysis. This point should be better discussed, namely its potential implications on the results and the reasoning for their use under the occurrence of temperature extremes driven by Saharan warm air intrusions. For instance, why are you using two variables that deliver similar information and not using variables that complement each other?

Figure 3: the colour scales are not adequate for representing potential temperature (I suggest a rainbow scale or similar). Please revise. Further, colours are not consistent between panels and the description in the caption.

Ln 140: please remove ", similar to".

Section 7: I suggest splitting the Discussion and Conclusions section into two separate sections.

Ln 275: IPCC in uppercase.

Ln 292: "as in (Sicard et al., 2022)". Please revise the citation formats throughout the manuscript.

Last paragraph of Section 7: the possible linkage of the upper-tropospheric anomalies underlying the onset and establishment of Saharan intrusions to the westerly eddy-driven jet stream over the North Atlantic, including anticyclonic/cyclonic wave-breaking processes, should be discussed.