Dear authors,

unfortunately, in its current form, the manuscript is still not ready for publication. Compared to the previous version, the inclusion of the GPT2w model is a significant scientific improvement (if the 1° by 1° degree resolution has been used, please confirm) and I would thank you for doing it. Also the English has improved (thank you), but not substantially enough. Please do not rely on the referees or the editing service of the journal to get the English right. With 6 authors, it is inacceptable to be of such a poor quality. Also please correct the absence of white spaces in lots of places in the manuscript. The Anonymous Referee #3 pointed out some places in the text where these are missing, but you should go through the entire manuscript and correct those accordingly.
The comments raised by David Adams about addressing all the sources of errors associated with PWV (and the calculation of ZHD which critically depends on the surface pressure) have not been taken into account in the updated version of the manuscript. Please do so. You should make the point that the error reduction due to your Tm model improvement might be negligible compared to the other error sources associated with the PWV retrieval from GNSS. Quantifying directly these errors is out of the scope of your paper, but, as commented by David Adams, you should at least point to their existence and give some estimates of their magnitude from the relevant literature (see also the second referee report of David Adams, please contact me if you do not have access to it).

I wish you good luck with the language and style editing of your manuscript and the inclusion of a description of error sources in the PWV retrieval from GNSS and I look forward to receiving a much improved manuscript.

With kind regards,

Roeland Van Malderen

Dear authors,

I thank you for including the uncertainty analysis asked for by a reviewer (David Adams) and me. With this, I accept the paper for publication in AMT. I would also like to draw your attention to a special issue in AMT, "Advanced Global Navigation Satellite Systems tropospheric products for monitoring severe weather events and climate (GNSS4SWEC)", see https://www.atmos-meas-tech.net/special_issue89.html, of which I was also guest editor. I would advise you to ask AMT (editorial@copernicus.org, with me in cc) if the paper could be included in this special issue, so that a larger visibility of your research in the GNSS community is guaranteed.

With kind regards,

Roeland Van Malderen