Ensemble hydro-meteorological prediction systems have higher forecasting skills than their deterministic counterparts, which in turn can improve risk assessment decision-making in operational water management. Ensemble forecasts are now common many operational settings, such as flood and drought forecasting, and can be used in applications from forecasting extreme events to optimisation of water resources allocation. However, moving from deterministic forecasting systems to a probabilistic framework poses new challenges but it also opens new opportunities for the developers and users of ensemble forecasts to improve their systems.

This session brings together scientists, forecasters, practitioners and stakeholders interested in exploring the use of ensemble hydro-meteorological forecast techniques in hydrological applications: e.g., flood control and warning, reservoir operation for hydropower and water supply, transportation and agricultural management. The session will also explore new forecast products and systems in terms of their implementation and practice for real-time forecasting.

Contributions will cover, but are not restricted to, the following topics:
- The design of ensemble prediction systems
- Requirements and techniques to improve the skill of hydro-meteorological ensemble forecasting systems
- Methods to bias correct and calibrate ensemble forecasts
- Methods to assess the quality or benchmark the performance of ensemble forecasts
- Approaches to deal with forecast scenarios in real-time
- Strategies for balancing human expertise and automation in ensemble forecasting systems
- Challenges of the paradigm shift from deterministic to ensemble forecasts
- Methods and products that include forecaster knowledge to improve the interpretation of ensemble forecasts
-Use of cost/loss scenarios for optimising systems
- Approaches for efficient training (including role-playing games) on the use and value of ensemble predictions.

The session welcomes new experiments and practical applications showing successful experiences, as well as problems and failures encountered in the use of uncertain forecasts and ensemble hydro-meteorological forecasting systems. Case studies dealing with different users, temporal and spatial scales, forecast ranges, hydrological and climatic regimes are welcome.

Solicited speaker Niko Wanders from Utrecht University: From seasonal forecasting to water management decisions: challenges and opportunities

The session is part of the HEPEX international initiative:

Co-organized as AS4.5/NH1.33, co-sponsored by HEPEX
Convener: Fredrik Wetterhall | Co-conveners: Rebecca Emerton, Kolbjorn Engeland, Tomasz Niedzielski, Jan Verkade
| Tue, 09 Apr, 10:45–12:30
Room 2.31
| Attendance Tue, 09 Apr, 08:30–10:15
Hall A

Attendance time: Tuesday, 9 April 2019, 08:30–10:15 | Hall A

Chairperson: Jan Verkade
A.112 |
Wouter Greuell, Wietse Franssen, and Ronald Hutjes
A.113 |
Katie Smith, Nicky Stringer, Maliko Tanguy, Michael Eastman, Simon Dadson, and Jeff Knight
A.114 |
Ignacio Martin Santos, Mathew Herrnegger, Jennifer Ostermüller, Kristina Fröhlich, and Hubert Holzmann
A.115 |
A seamless assessment of daily to seasonal meteo-hydrological prediction uncertainties for the monsoon driven hydrology in East India
Lisei Köhn-Reich, Gerd Bürger, and Axel Bronstert
A.116 |
Erik Schmitt Quedi and Fernando Mainardi Fan
A.117 |
Alberto Assis dos Reis, Wilson S. Fernandes, Maria-Helena Ramos, Jan Verkade, Albrecht Weerts, and Fredrik Wetterhall
A.118 |
Jan Verkade, Patricia Trambauer, Willem van Verseveld, and Albrecht Weerts
A.120 |
Bikas Chandra Bhattarai, John Faulkner Burkhart, Lena Merete Tallaksen, Frode Stordal, Chong-Yu Xu, and Felix Nicholas Matt
A.121 |
Vinícius Siqueira, Albrecht Weerts, Jan Verkade, Bastian Klein, Fernando Fan, Rodrigo Paiva, and Walter Collischonn
A.122 |
James Bennett, David Robertson, and Prasantha Hapuarachchi
A.123 |
Jon Skoien, Peter Salamon, Konrad Bogner, and Fredrik Wetterhall
A.124 |
Yuanhong You, Chunlin Huang, Ying Zhang, and Jinliang Hou
A.125 |
Erick Fredj, Theodor Bughici, Naftali Lazarovitch, and Eran Tas
A.126 |
Jessica Neumann, Louise Arnal, Liz Anspoks, Hannah Cloke, Susan Manson, Tim Norton, Elisabeth Stephens, and Louise Wolfenden
A.127 |
Lorenzo Alfieri, Ervin Zsoter, Hannah Cloke, Elisabeth Stephens, Shaun Harrigan, Feyera Aga Hirpa, Christophe Lavaysse, and Peter Salamon
A.128 |
Ensemble approach for rainfall forecasting
Harshil Shah and Ravikumar Ganti
A.129 |
Schalk Jan van Andel, Anouk van Stokkom, Gerben Dekker, and Anne Margot Leicher
A.130 |
Christel Prudhomme, Fredrik Wetterhall, Maria-Helena Ramos, Andy Wood, Qj Wang, Jan Verkade, Ilias Pechlivanidis, Marie-Amélie Boucher, and Rebecca Emerton