1. “Probability forecast use” study Edwin Welles and Jan Verkade February 2012

2. November 30, 2011 Theme of present project: probability forecasting

3. November 30, 2011 “How to realise the benefits of probability forecasting?” Probability forecasting brings benefits to forecasters and end users Having a forecasting system that estimates predictive uncertainty is probably not sufficient to realise these benefits  What needs to be done in addition to having a probability forecast?  Present project aims to preliminary answer this question  By eliciting expertise/judgement from forecasters and end-users

4. November 30, 2011 Present project: use of probability forecasts Looking at aspects such as: visualisation communication decision-making verification training “downstream” decision support systems business procedures

5. November 30, 2011 Project participants Flood Control 2015 programme (funding) US National Weather Service, NCRFC Meuse River Forecasting Centre (RWS, Dienst Limburg) Water board Noorderzijlvest Scottish Environment Protection Agency (TBC) Why Deltares? Delft-FEWS (CHPS) related research PhD research on predictive hydrological uncertainty The Netherlands can benefit from US prediction enterprise

6. November 30, 2011 Case studies not too large straightforward forecast – decision – warning – response chain (not too many stakeholders involved) largely based on desk research and interviews desk research: review of current operational procedures interviews: elicit expertise and/or expert judgement from forecasters and emergency managers  “how would your tasks/responsibilities change if probability forecasts were to be introduced?”

7. November 30, 2011 Water Board “Noorderzijlvest” Water Board: responsible for maintaining water levels in polder districts within acceptable levels (Fully controlled systems, well below MSL) 2010 event: flood warning called, but nothing happened Hydrologist was blamed Way forward: probability forecasts

8. November 30, 2011 Water Board “Noorderzijlvest” November 2011: forecasting – warning – response exercise Lessons: interpretation of probability forecasts not an issue information overload is decision makers: with these forecasts, I don’t have to make my own estimates of the inherent uncertainties probability forecasts used to devise scenarios (worst case)

9. November 30, 2011 Study deliverables Description of “best practices” of using probability forecasts within FFWRS, from multiple case studies Inventory of likely challenges / possible obstacles for effectively using probability forecasts Seminar, Report, scientific article (while we’re at it: collect relevant reports from earlier, related studies  bibliography, links and downloads will be published on the Deltares wiki pages)