The EGU interactive community platform
The EGU interactive community platform
EGUsphere
Preprints
Preprints
https://doi.org/10.5194/egusphere-2026-2283
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/egusphere-2026-2283
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
Preprints
29 Apr 2026
 | 29 Apr 2026
Status: this preprint is open for discussion and under review for Geoscientific Model Development (GMD).

Extending Medium-Range Global Flood Forecasts: The Google Global Flood Forecasting Model Version 2

Deborah Cohen, Rony Amira, Rom Aschner, Yuval Carny, Ben Feinstein, Hadas Fester, Shmulik Fronman, Martin Gauch, Oren Gilon, Rotem Green, Avinatan Hassidim, Daniel Klotz, Frederik Kratzert, Dan Korenfeld, Gila Loike, Amit Markel, Yossi Matias, Rotem Mayo, Asher Metzger, Benny Mosheyev, Aviel Niego, Stephanie Rees, Emily Reinstein, Amitay Sicherman, Guy Shalev, Omri Shefi, Yuval Shildan, Ido Zemach, Oleg Zlydenko, and Grey Nearing

Abstract. This paper evaluates an updated flood forecasting system that significantly extends reliable lead times. We evaluated this updated model (v2) against the prior system (v1) and established third-party benchmarks across 1,223 global test basins. The primary finding is that the v2 system extends the reliable predictive horizon by 6 days in gauged basins and 1 day in ungauged basins relative to the v1 nowcast, as measured by the Nash Sutcliffe Efficiency. Along with this paper, we release an open-source codebase for training both the v1 and v2 forecast models with the open-source Caravan dataset.

How to cite. Cohen, D., Amira, R., Aschner, R., Carny, Y., Feinstein, B., Fester, H., Fronman, S., Gauch, M., Gilon, O., Green, R., Hassidim, A., Klotz, D., Kratzert, F., Korenfeld, D., Loike, G., Markel, A., Matias, Y., Mayo, R., Metzger, A., Mosheyev, B., Niego, A., Rees, S., Reinstein, E., Sicherman, A., Shalev, G., Shefi, O., Shildan, Y., Zemach, I., Zlydenko, O., and Nearing, G.: Extending Medium-Range Global Flood Forecasts: The Google Global Flood Forecasting Model Version 2, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2026-2283, 2026.
Received: 21 Apr 2026 – Discussion started: 29 Apr 2026

Competing interests: All authors are employed by their primary affiliation, Google, the organization that developed and operates the Google Global Flood Forecasting system and the associated open-source Google Hydrology codebase evaluated in this manuscript. The authors declare that they have no other competing interests.

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this paper. While Copernicus Publications makes every effort to include appropriate place names, the final responsibility lies with the authors. Views expressed in the text are those of the authors and do not necessarily reflect the views of the publisher.
Share
Deborah Cohen, Rony Amira, Rom Aschner, Yuval Carny, Ben Feinstein, Hadas Fester, Shmulik Fronman, Martin Gauch, Oren Gilon, Rotem Green, Avinatan Hassidim, Daniel Klotz, Frederik Kratzert, Dan Korenfeld, Gila Loike, Amit Markel, Yossi Matias, Rotem Mayo, Asher Metzger, Benny Mosheyev, Aviel Niego, Stephanie Rees, Emily Reinstein, Amitay Sicherman, Guy Shalev, Omri Shefi, Yuval Shildan, Ido Zemach, Oleg Zlydenko, and Grey Nearing

Status: open (until 24 Jun 2026)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
Post a comment Subscribe to comment alert
Deborah Cohen, Rony Amira, Rom Aschner, Yuval Carny, Ben Feinstein, Hadas Fester, Shmulik Fronman, Martin Gauch, Oren Gilon, Rotem Green, Avinatan Hassidim, Daniel Klotz, Frederik Kratzert, Dan Korenfeld, Gila Loike, Amit Markel, Yossi Matias, Rotem Mayo, Asher Metzger, Benny Mosheyev, Aviel Niego, Stephanie Rees, Emily Reinstein, Amitay Sicherman, Guy Shalev, Omri Shefi, Yuval Shildan, Ido Zemach, Oleg Zlydenko, and Grey Nearing

Data sets

Model Data Grey Nearing, Frederik Kratzert, Martin Gauch https://doi.org/10.5281/zenodo.19676842

Model code and software

GoogleHydrology Grey Nearing, Omri Shefi, Amit Markel, Frederik Kratzert, Martin Gauch https://github.com/google-research/flood-forecasting

Deborah Cohen, Rony Amira, Rom Aschner, Yuval Carny, Ben Feinstein, Hadas Fester, Shmulik Fronman, Martin Gauch, Oren Gilon, Rotem Green, Avinatan Hassidim, Daniel Klotz, Frederik Kratzert, Dan Korenfeld, Gila Loike, Amit Markel, Yossi Matias, Rotem Mayo, Asher Metzger, Benny Mosheyev, Aviel Niego, Stephanie Rees, Emily Reinstein, Amitay Sicherman, Guy Shalev, Omri Shefi, Yuval Shildan, Ido Zemach, Oleg Zlydenko, and Grey Nearing
Metrics will be available soon.
Latest update: 01 May 2026
Download
Short summary
We improved our global river model to provide earlier, more reliable streamflow predictions. Testing over approximately 1,000 watersheds, we found it predicts river flows up to six days further into the future for monitored rivers, and one day further for unmonitored ones. Releasing our code publicly empowers the science community to improve global water forecasting.
Read more
Share