Dear authors,

all three reviewer approve the significance and presentation of the topic. Regarding the scientific quality of the paper all reviewers raised important comments, which you should address by a point by point response.
Particular comments on model uncertainties and the assumption of stationary conditions are raised by all three reviewers. I believe that there are relevant concerns and I highly recommend to stress this more in the revised version. I support reviewer one who recommended an additional study (using split sample tests) or at least add a more elaborated discussion of the phenomenon and its impacts.
A second important point relates to the question, if you study sample of six catchments is large enough to draw general conclusions. Reviewer two believes that the variability of the six catchments under study is representative enough for general conclusion, while reviewer three (who is probably a much better expert on hydrological variability in Norway) raised the concern of the limited sample size. I would like to see an increasing number of catchments or the use of gridded data, as recommended by reviewer three. However, if this is too much workload, I recommend to discuss this problem in more detail to see for which type of catchment your results are representative for and where your results my be more uncertain.

For the other reviewer comments, I believe that you can change or extend the text, which is needed for clarification. After addressing the point by the reviewers, I believe that the paper can be published in HESS.

Best regards
Ralf Merz

Dear Authors,

Thank you for revision your original manuscript. One reviewer acknowledged the revision and rated the current manuscript ready for publication. The second, more critical reviewer or the original manuscript, acknowledges the changes but still gives some valuable comments for further improvement.

I think there are some smaller changes in text needed before publication:
I agree with reviewer 2 that the motivation of the study should be stated more clearly in respect to available literature (e.g. Hall et al., 2014). In particular, I think your study aims towards closing the gap of Lawrence and Hisdal (2011) by looking at catchment with mixed regimes in more detail. Please add another sentence on that. I also agree with reviewer 2 on the comments on parameter stationarity and the choice of the reference periods in respect to future climate changes.

Another point of criticism of reviewer 2, to which I agree, is the fact that you analyse only 6 catchments. Although the catchments may cover a wider range of climatic condition, the small number of catchments may to small to be generalized without further thinking. Hence I recommend to add some comments in the conclusion section, how what can be generalise and where are the limits due to the small number of catchments under study.