12 May 2023
 | 12 May 2023
Status: this preprint is open for discussion.

Assessing the ability of a new seamless short-range ensemble rainfall product to anticipate flash floods in the French Mediterranean area

Juliette Godet, Olivier Payrastre, Pierre Javelle, and François Bouttier

Abstract. Flash floods have dramatic economic and social consequences, and efficient adaptation policies are required to reduce their impacts, especially in a context of global change. Developing more efficient flash flood forecasting systems can largely contribute to these adaptation requirements. The aim of this study was to assess the ability of a new seamless short range (0–6 h) ensemble quantitative precipitation forecast (QPF) product, called PIAF-EPS and recently developed by Météo-France, to predict flash floods when used as input of an operational hydrological forecasting chain. For this purpose, eight flash flood events that occurred in the French Mediterranean region between 2019 and 2021 were reanalysed, using a similar hydrological modeling chain to the one implemented in the French “Vigicrues-Flash” operational flash flood monitoring system. The hydrological forecasts obtained from PIAF-EPS were compared to the forecasts obtained with different deterministic QPFs from which PIAF-EPS is directly derived (i.e. the AROME-NWC numerical weather prediction model, and the deterministic PIAF product). The verification method applied in this work uses scores calculated on contingency tables, and combines the forecasts issued on each 1 km2 pixel of the territory. This offers a detailed view of the forecast performances, covering the whole river network and including the small ungauged rivers. The results confirm the added value of the ensemble PIAF-EPS approach for flash flood forecasting, in comparison to the different deterministic scenarios considered.

Juliette Godet et al.

Status: open (until 05 Jul 2023)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse

Juliette Godet et al.

Juliette Godet et al.


Total article views: 163 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
110 45 8 163 1 1
  • HTML: 110
  • PDF: 45
  • XML: 8
  • Total: 163
  • BibTeX: 1
  • EndNote: 1
Views and downloads (calculated since 12 May 2023)
Cumulative views and downloads (calculated since 12 May 2023)

Viewed (geographical distribution)

Total article views: 168 (including HTML, PDF, and XML) Thereof 168 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
Latest update: 08 Jun 2023
Short summary
This article results from a research master project which was part of a natural hazards program developed by the French Ministry for the Environment. The objective of this work was to investigate one of the possible ways to improve the operational flash flood warning service: the addition of rainfall forecasts upstream of the forecasting chain. The results showed that the tested forecast product, which is new and experimental, has a real added value compared to other classical forecast products.