Gavin Robbins Senior Hydrometeorologist Flood Forecasting Centre, Exeter, UK Identifying current capabilities and areas of improvement to flood guidance information EMS and ECAM 2015 © Crown copyright

 Flood Guidance Statement (FGS)  FGS verification system  Example performance  Discussion of results  Conclusion Acknowledgements: Emily Shipton, Julia Perez and JBA Associates Overview

Flood Guidance Statement

Flood Risk Matrix Likelihood: Very Low 60%  109 counties/authorities  4 sources of flooding  5 day forecast  2180 daily forecasts

A busy FGS

What goes into the FGS Local Centres

 Need to know  Performance reporting:  Customers (confidence)  Funding bodies  Target setting  Identifying/demonstrating improvement How successful is our forecasting?

 On-line  Built by an external contractor (JBA)  Implemented April 2015  Data from June 2013:  Forecast (location, source, impact, likelihood)  Impact observations  Range of displays  Varying complexity  Filter by county, area, lead time, severity, source, time period. FGS Verification System

 Flood Risk Forecast  Impact Forecast  Impact Observation Simple Forecast v Observation Display

Flood Risk Forecast Observed Impacts

Detection Statistics – Probability of Detection

Probability of Detection vs Lead Time Significant and Severe Flooding Impacts

Reliability  Surface water flooding.  Day 2  June 2013 – April 2015

Reliability  Coastal flooding.  Day 3  June 2013 – April 2015

Reliability  River flooding  Day 3  June 2013 – April 2015

Lead time of first correct forecast  Significant and Severe Impacts (June 2013 – April 2015) River Surface Water CoastalGroundwater

Data period is critical April 2014 – April 2015 Surface Water June 2013 – April 2015

Data period is critical April 2014 – April 2015 Fluvial Reliability June 2013 – April 2015

Concluding comments  Many uses for performance information.  Successful performance and areas of improvement  Processing and clear explanation.  Reporting period must be considered.  FFC has good detection rates.  Warns effectively with suitable lead time.  Over cautions in some circumstances.  Reliant on thorough observations.

Thank you for listening