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Met Office Verification -status. Clive Wilson, Presented by Mike Bush at EWGLAM Meeting October 8-11, 2007. 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
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Met Office Verification -status Clive Wilson, Presented by Mike Bush at EWGLAM Meeting October 8-11, 2007
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
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
NAE and UK4 verification • Operational: • UK index – surface parameters • Verification against radar composites (Nimrod) • “fuzzy” – Fractional skill score • Research • Intensity-scale
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/So, So=value at March 2000
Validation monthly precipitation against gauge analysis gauges difference UK4
Intensity-scale 4km model precipitation Highlights intensity-scales where worse than random forecast
Verification (Fractional Skill Score) July 2007
Verification (Fractional Skill Score) August 2007