Skilful seasonal forecasts of streamflow over Europe?

Skilful seasonal forecasts of streamflow over Europe?

Contributed by Louise Arnal, University of Reading & ECMWF Editor’s Note: Don’t miss the brilliant cartoon summary at the bottom of this post! Over recent decades, seasonal streamflow forecasting methods have evolved and diversified, reflecting changes in our scientific understanding of streamflow predictability on seasonal timescales and our increasing computer power. The first operational model-based ensemble seasonal streamflow forecast, called the ESP1,2 (ensemble streamflow prediction), relies on the correct knowledge of the initial hydrological conditions (IHC; i.e. of snowpack, soil…

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Risk Communication for Cyclone Early Warning – Do people get the message, and understand what it means for them?

Risk Communication for Cyclone Early Warning – Do people get the message, and understand what it means for them?

Contributed by Bapon Fakhruddin, Senior DRR and Climate Resilience Specialist, Tonkin+Taylor & Co-chair of the Risk Interpretation and Application of IRDR/ICSU Every year, New Zealand is impacted by ex-tropical cyclones (ETCs) – typically, one ETC makes landfall per year, between the months of November and April. As tropical cyclones approach New Zealand, they begin to lose their strength and undergo extratropical transition (ETT). Some of these weather systems are as large as New Zealand’s North Island when considering the full diameter…

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Using ensemble forecasts to inform risk-based operations of a reservoir in Northern California

Using ensemble forecasts to inform risk-based operations of a reservoir in Northern California

Contributed by:  Chris Delaney, Sonoma County Water Agency; John Mendoza, Sonoma County Water Agency; Brett Whitin, California Nevada River Forecast Center; Rob Hartman, Consultant Lake Mendocino is a reservoir located in Mendocino County, California, about 110 miles north of the City of San Francisco. This small 144 million cubic meter reservoir (Figure 1) releases water into the Russian River and provides both flood protection and water supply to downstream communities. Lake Mendocino is cooperatively managed by 2 government offices: the…

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Hydropower management in Brazil and water forecasts – Interview with Alberto Assis dos Reis

Hydropower management in Brazil and water forecasts – Interview with Alberto Assis dos Reis

Alberto is an engineer and hydrologist at Cemig, a Brazilian power company headquartered in Belo Horizonte, the capital of the state of Minas Gerais, and is currently starting a PhD work at the Federal University of Minas Gerais (UFMG). His PhD project involves also collaboration with three other organizations in Europe, strongly involved in Hepex: Irstea (France), Deltares (The Netherlands) and ECMWF (UK). He was recently visiting these organizations and, when he came to France, I took the opportunity to…

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Risk aversion and decision making using ensemble forecasts

Risk aversion and decision making using ensemble forecasts

by Marie-Amélie Boucher and Vincent Boucher Assessing the value of forecasts is a very popular topic among the HEPEX community. The assessment of forecast value is highly dependent on the purpose served by the forecasts. For the specific problem of decision-making related to flood mitigation, Murphy (1976, 1977) proposed the use of the cost-loss ratio framework. The vast majority of papers related to the assessment of forecast value for flood mitigation adopt this framework, so one could think that everything is…

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