This manuscript tries to understand a long-standing problem in the context of the Indian monsoon: the relationship between intraseasonal oscillations and the generation of low-pressure systems. Few recent studies have shown the association, but here the authors provide a detailed overview and try to understand how LPS are modulated by ISO phases in both rainfall intensity and propagation speed. Dynamical and thermodynamical aspects are investigated and the authors concluded that the nonlinear frictional convergence and anomalous boundary layer convergence both are important for LPS intensification. This work has immense scientific importance in understanding monsoon dynamics. I enjoyed reading it! There are a few points that still need to be clarified:

1. Line 5: Provide some explanation about the phases before this statement. How do you get the phases?

2. Line 47: The results presented in Figures 1-3 are interesting. While you discussed data and methods later in Section 2, putting these figures in the introduction does not tell the source of the dataset. I suggest moving these figures to the main Results and keeping a discussion based on earlier studies in the introduction. 

3. Line 59: Fig. 3 instead of Fig. 2.

4. Lines 109-110: Which region did you choose for the analysis?

5. Figure 4: What is the meaning of the color over the grid points where there are no LPS formed during the period of analysis (e.g.,  near the Himalayan foothills or the western equatorial Indian Ocean)?

6. Line 140: What do you mean by "half a phase"?

7. Line 143: I could see both phases 1 and 2

8. Lines 146-147: How do you conclude this if the "amplitude is insufficient for the phase to be well defined"? Did you disregard the amplitude and considered just the phase in these cases?

9. Figure 5 and text: How do you calculate LPS propagation velocity?

10. Lines 160-165: The large-scale circulation during the genesis day of the LPS could be very different when the LPS is matured (maybe 4-5 days later). How do you interpret the results? This analysis is based on the genesis days as I understand it.

11. Figure 6: Is this precipitation on genesis day or averaged over the lifespan of the LPS? If it is the later case as it appears looking into the number of samples, how do you consider the BSISO phase as LPS life may span across multiple BSISO phases?

12. Figure 6: "all such LPSs" - including those in phase 0?

13. Lines 190-195: Phase 5 in both cases increases the anomaly in rainfall: this could be related to the fact that LPS may have a lifespan across different BSISO phases.

14. Lines 275-280: Did you do the compositing based on BSISO phase 5 days without any LPS activity and with LPS activity, and saw the differences?

15. Line 285: this is rather difficult to conclude here.

Looking forward to the answers and revised manuscript.

Monsoon low pressure systems (LPS)  are responsible for a major part of summer monsoon rainfall over the Indian subcontinent and are also linked with extreme precipitation. This timely paper investigates the relationship between monsoon LPS  and Boreal summer intraseasonal oscillations (BSISO), one of the dominant modes of intraseasonal variability affecting the South Asian monsoon. The authors show in detail the way BSISO affects the LPS genesis and precipitation. They find the modulation of LPS by BSISO occurs through dynamic rather than thermodynamic changes. Using the QG-omega equation they show that the anomalous vorticity changes are driven mostly by the differential vorticity advection and further explore how the various factors affect the structure of anomalous vorticity. Overall, I find the results are sufficently  novel and of great scientific importance. I have a few clarifications/corrections listed below, and I’d be happy to recommend it for publication once these points are addressed.

Comments : 

L12-13: The phrase "Contributions from BSISO and anomalous BSISO circulations " is confusing. Better to rephrase contributions from BSISO as from the “mean/background” BSISO circulation.

L37 : Do phases 4 and 5 bring enhanced convection over all of India or just a specific region there?

Liked this novel way of presenting different phases in Fig1. Does individual maps of precipitation for various phases show similar behaviour of northward propagation of the precipitation peaks. 

I would suggest moving the figures 1-3 from introduction to results section. 

L59-65: I know it’s been cited earlier in the introduction but it might be a good thing to mention the earlier studies that show intensification of background vorticity related to BSISO here.

Fig 4: Would it be meaningful to color the grid boxes with no LPS? How sensitive is the classification with the grid sizes and the classification criteria. It might be better to use k-means clustering or may be a simple criterion like the phase to which the majority of  LPS points  within some radial distance belong to.

L135 : Lots of phase 7 and 8 points are also there over Sri Lanka.

L140: It’s unclear what half phase means.

L144: Any reason why increased TCWV would follow LPS genesis. Wouldn’t TCWV be a factor determining the LPS genesis?

Figure 6:  Are these the precipitation plots for all the LPS times and not just for the genesis? If so, how are the phases assigned for the later stages of LPS. Is it based on the phase at the time of genesis or does it change with time along the LPS track? 

Figure 6 and in other places too : What does “all such LPSs” refer to, does it include phase 0?

L186-188: What would be the nature of the changes in the background environment that result in uniform increase in rainfall. For eg, even a uniform increase in moisture would result in precipitation increasing in the region of convergence but  not a uniform increase everywhere.

L189: “rotated two phases earlier”,  the maxima is still at phase 5 isn’t it? Only the negative anomalies shift. Any reasons for that.

L268: Wouldn’t vorticity always have a maxima in the centre as you are tracking the LPS using vorticity maxima.

L285-286:  Can this be deduced from the storm centre analysis alone.

L288: Fig13 instead of 15.

Since it’s the phase rather than the amplitude of BSISO that’s affecting the LPS modulation, I’m just curious on how the background states vary for phase 0. Are the background conditions similar across the phases irrespective of the amplitude?

Typos : 

L43 : “extrems”

This paper proposed to investigate the relationship between the Boreal Summer Intraseasonal Oscillation and the monsoon low-pressure systems, which is a novel topic with respect to the dynamics near the Indian ocean. The authors studied the precipitation, water vapor, vorticity and the SLP genesis during all eight phases of BSISO and selected phases 2 and 5 as representatives of opposing phases. The energetics was then illustrated through linearization and omega function based on the two typical phases. The nonlinear features in the vertical velocity and vorticity within the SLPs were highlighted by subtracting the linear part from the full fields.

The manuscript is nicely drafted but still has some problems that need to be fixed before publishing

Major opinions:

1. Are Figures 1,2 and 3 colorblind-friendly? I know you are trying to use rainbow colors to represent different phases but should be careful with the selection of colors. It looks a bit messy especially when you assign three levels of brightness to each color. Here are two potential options to better show these plots:

        1). Instead of using darkness or brightness to represent the intensity, try using contours with different line types, for example, the one on the left, use dashed contours for >20%, solid contours for 100% and no contours for 50%

        2). Separate each plot into three according to the intensity.

2. In line 34, you stated that BSISO is identical to MJO. The phases of MJO are usually shown by the outgoing long-wave radiation, how about BSISO? Is it often shown by OLR or precipitation or any other fields? Can you make a schematic plot to show the eight phases? An amplitude-latitude or an amplitude-time or a time-latitude diagram is suggested when introducing the eight phases.
3. In Line 64. The “symmetric” feature also exists in part of the TCWV. So it is not plausible enough to be considered a “difference”.

Minor opinions:

1. A typo at Line 59, should be Fig.3.
2. It should be marked when the first time the abbreviation “TCWV” shows up.
3. Please write the full name of BSISO in the title.
4. Please write the full name of ERA5 in the subtitle in Line 90
5. When you say the LPS genesis is half a phase behind the vorticity maxima from Line 140 to 145, what do you mean by “half a phase”. Can you do a lag regression to show that? Show the order of water vapor, vorticity and LPS genesis reaching their maxima using lag regressions or any better method.
6. A question: why do you use relative latitudes and longitudes instead of the absolute ones in most of your plots? If you would like to state the topologies and locations, the absolute ones would be more helpful.

I’m looking forward to seeing your response to the abovementioned questions.