EFAS EPS Based Forecasts: In-depth Case Study Analyses and Statistical Evaluation of Summer 2005 and Spring 2006 Flood Forecasts

This study deals with the analysis and interpretation of case studies in view to defining rules to an objective and statistical evaluation of ensemble flood forecasts from the European Flood Alert System (EFAS). First, we investigate EFAS forecasts on a flood-event basis. The aim is to investigate the ability of EFAS flood forecasts based on Ensemble Prediction System (EPS) to provide earlier warning, comparatively and/or complementarily to the forecasts based on deterministic weather forecasts. Secondly, a statistical analysis of the flood events forecasted over the flood-prone periods of summer 2005 and spring 2006 is performed. The analysis focuses on i) the statistical evaluation of hits, misses and false alarms as a function of the number of EPS-based simulations exceeding a given EFAS flood alert threshold and ii) on the comparative analysis of gain in preparedness (early forecasting) when operational alert rules are applied on both forecasts based on probabilistic and deterministic weather forecasts to define a potential flooding situation. The analyses were performed over a number of representative points selected throughout the Danube and the Elbe river basins.

RAMOS M-H.;  THIELEN DEL POZO Jutta;  BARTHOLMES Jens; 

2007-12-05

OPOCE

JRC41103

https://publications.jrc.ec.europa.eu/repository/handle/JRC41103,