The reasoning for rejection was that the approach taken was simply a pre-form of calibration using MRC analyses, in essence in my view a form of hydrological signature evaluation. I in part agree with these comments and in particular that the authors call their approach 'calibration free' which I cannot agree with and does need to be stripped out. The difficulty here is then if the authors can provide a compelling manuscript that tones down to some extent the claims of calibration free analyses and more delves into what they have achieved and how it better relates to an ungauged analyses as part of this work.

My view is that the reviewers provided a very valuable set of comments and equally the authors provided thoughtful responses which are for many of the points raised an excellent approach to changing the manuscript towards publication. However I remain less convinced by one of the core response to the 1st reviewer in that turning this into an equifinality discussion. Partly because simply they have not done any uncertainty evaluation of these parameter combinations to understand the spread of likely outputs, nor have they considered or treated any of the observations as in any way uncertain and focused on standard performance metrics!

So if the authors respond as they say they will to the comments raised then I believe this is a good starting point to consider the paper for publication in HESS. However this will need to be re-reviewed and I strongly suggest the authors need to:
1) Properly evaluate and discuss the issues of using streamflow signatures (in this case MRC) as a form of calibration that they can be considered (there are ways this could be assessed as to the strength of this information in comparison to the overall calibration scheme). I suggest further in depth analyses is needed here that needs to be compelling…
2) Tone down any comments of this being ‘calibration free’ unless they can bring in the work of their colleagues where these parameters have been attributed to catchment characteristics and show therefore this as the main comparison made. I would strongly suggest the paper is more unique and novel if this could be related to some form of true ‘un-gauged’ analyses
3) I would add that there is a need to better articulate in the paper what parts of the recessions they have extracted to fit the parameters ‘pre-calibration’ as it wasn’t clear to me how these series had been quantified. I would also be interested in knowing as part of this how consistent these recessions are from the overall set used and how much variability there is in this characteristic for a few example catchments.
So I am encouraging the authors to make changes to their manuscript and to address the reviewer points raised but this will need to be re-assessed by further review and particularly on the 1st 2 points above to confirm this would be a novel and worthy paper for final publication in HESS, Jim Freer

We have now collected two reviews for the revised manuscript. I agree with reviewer 2 that there needs to be some additional clarity about the assumption choices that could be made and the additional minor points raised. If the authors respond to that request and ensure discussion on this is implemented then I see no reason to not complete and publish the manuscript, thanks all for their time on this, and especially the authors for changing the manuscript significantly based on the first reviews, Jim

Thanks for editing further the manuscript. I believe you have appropriately addressed the reviewers concerns (which were minor) and now the paper is ready for publication, best wishes, Jim