1. Page 1© Crown copyright 2005 Met Office Verification -status Clive Wilson, Presented by Mike Bush at EWGLAM Meeting October 8- 11, 2007

2. Page 2© Crown copyright 2005 Outline  Main systems – area and station  Use same packages for operations and R&D  Mesoscale Limited area  UKindex  Trials  Precipitation validation – radar, gauges  High resolution  Fractions skill  Intensity scale

3. Page 3© Crown copyright 2005 Main systems  2 systems  Ver – only stores area averaged statistics/scores  Obs – surface, upper air, satellite winds, aircraft, radar precipitation  Analyses  Continuous and categorical statistics, skill scores  SBV- station based relational database (Oracle)  Enables greater flexibility  Conditional verification  Used for many operational and research forecasts  Model  Site specific  Forecasters  Continuous and categorical statistics, skill scores

4. Page 4© Crown copyright 2005 NAE and UK4 verification  Operational:  UK index – surface parameters  Verification against radar composites (Nimrod)  “fuzzy” – Fractional skill score  Research  Intensity-scale

5. Page 5© Crown copyright 2005 UK Index  Screen level Temperature, 10m wind  MSE skill  6h precipitation, visibility, cloud cover, cloud base  Equitable threat score, 3 thresholds  All WMO 03, UK stations  Equal weights to T+6 to +48 by 6h  Equal weights to each parameter  36 month contingency tables, running means  I=100*S/S o, S o =value at March 2000

6. Page 6© Crown copyright 2005 UK index Thresholds and weights

7. Page 7© Crown copyright 2005

8. Page 8© Crown copyright 2005 Trials verification –use same verification as operational

9. Page 9© Crown copyright 2005 Validation monthly precipitation against gauge analysis UK4 gauges difference

10. Page 10© Crown copyright 2005 SBV error maps

11. Page 11© Crown copyright 2005 Intensity-scale 4km model precipitation Highlights intensity-scales where worse than random forecast

12. Page 12© Crown copyright 2005 Verification (Fractional Skill Score) July 2007

13. Page 13© Crown copyright 2005 Verification (Fractional Skill Score) August 2007

14. Page 14© Crown copyright 2005 Questions & Answers