Dear authors

the manuscript is close to being accepted. I want to congratulate you to a very well-written and easy to comprehend paper. Even though the construction of a "good" precipitation interpolation approach may seem to be more like a textbook exercise and the issue itself is probably only a minor aspect of the full FLEXPART, your paper nicely demonstrates and precisely outlines all the small caveats that one can face and I appreciate the detailed report on this issue. It was pleasure to read the manuscript.
A few technical corrections should be implemented before acceptance (the page numbers refer to manuscript version with highlighted differences):
1.) On page 2 last sentence: you may remove the "(" ")"
2.) Caption of Figure 8: The third sentence describing the dark blue line should appear after "a)"
3.) Fig. 10 and 11: top right corner "IA2m", the captions says "IA2"!?
4.) page 26, line 16: "details"
5.) Table 4: NMSE should not have units mm h^-1
6.) Could you motivate in one sentence why you evaluate higher order moments like kurtosis? Is it a relevant metric for precipitation statistics or is it merely a common easy to evaluate statistic measure?
7.) section 4.3: you may rename 2IA1m" to "speed-optimized Interpolation Algorithm (IA1s)" to avoid the misleading analogy IA2 -> IA2m.

Best wishes,
Simon Unterstraßer