Dear Authors:
I have received two reviews of the manuscript. The first anonymous Referee provided no substantial comments on the manuscript. The second anonymous Referee provided extensive comments and recommended re-considering the manuscript after major revisions. I generally agree with the major criticism of the 2nd Referee and offer the authors re-submitting the revised version of the manuscript for further review by the Editor.

Alexander Gelfan,
Handling Editor

I have found that the authors took into account the main criticisms of both referees that resulted in improvement of the manuscript. At the same time, the responses to two comments of the 2nd referee, who suggested re-considering the manuscript after major revisions, look rather formal for me. Thus, I suggest the authors to consider the following criticisms of the 2nd reviewer, revise the manuscript and resubmit within a reasonable time for final editor’s decision.

1. The 1st Referee expressed reasonable concern that the presented results don’t allow a reader to evaluate the model’s applicability because of short duration of the calibration/validation period (2 years) and suggested prolonging it. I have checked the streamflow data availability for the Vermilion River at Pontiac and found that there are at least 8-year period of continuous daily records from 2009 till 2017. Importantly, this period covers the SMOS satellite data. Thus, I strongly recommend taking into account the criticism of the referee and prolonging the study period.

2. I consider that the next comment of the referee also requires more serious attention. His/her question related to ability of the XAJ model for reproducing soil moisture dynamics under frozen conditions. This ability is important because frequent soil freezing events in winter seasons are specific for the study basin. In their response to this comment, the authors argued that “XAJ model is very good at simulating the flow even during the winter season”. In my experience, this argument does not sufficient and good model’s performance in reproducing streamflow does not confirm the model’s performance in describing water content of frozen soil. Moreover, it is not too difficult tuning the model to short (2 years only) time-series of streamflow data without considering frozen conditions at all. Unfortunately, I could not find examples of the XAJ model’s application for these conditions (the mentioned two-page paper Zhou et al, 2008 can hardly be considered as a convincing example). Thus, I recommend adding more results and discussion confirming ability of the XAJ model for reproducing soil moisture dynamics under frozen conditions