page 1© crown copyright 2005 srnwp – revised verification proposal clive wilson, cosmo annual...
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© Crown copyright 2005 Page 1
SRNWP – Revised Verification Proposal
Clive Wilson, COSMO Annual Meeting September 18-21, 2007
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Original Draft Proposal (not submitted to EUMETNET)
2 aims Development of a common verification package Realization of an operational model intercomparison
Further aims Provide new methods (fuzzy etc) Allow non-GTS observation data Radar composites (esp. OPERA)
Responsible Member would: Write & maintain code of package Compute comparison scores, website & archive Find NMS(or ECMWF) to host non-GTS data hub Motivate NMSs to contribute non-GTS data to hub
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Not submitted because:
Not fully agreedToo ambitious- underestimate time/effort needed to develop new code & package
No one indicated wish to be responsible member
Major centres and consortia already had most of proposed functionality in own packages
EUMETNET reluctant to agree proposed cost (1FTE scientist + travel +25% programme manager)
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New (draft) proposal – staged aims
1. Inititiate a “realistic” intercomparison based on Exchange of forecasts from main models at 3-4 centres
(format – GRIB then interoperability to define) Met Office NAE - 12km Hirlam reference - 15km Aladin France - 10km COSMO-EU - 7km
Use existing packages Accept different station selection, QC (difficult to
mandate/change at op. centres) Verify common scores for same parameters over
common areas Compare and contrast results to reach “consensus” Extension of existing precip. verification done by Met
Office
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External Met Office website- European Precipitation comparison
http://www.metoffice.gov.uk/research/nwp/numerical/precipitation/emip.html
user : viewprecip
pwd: rain4you
Models: Hirlam reference COSMO-EU (DWD lokall) Aladin (MeteoFrance) UM – North Atlantic European COSMO-7 (MeteoSwiss)
Verified against British Isles Nimrod radar composite
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External Met Office website- European Precipitation comparison
24h accumulations thresholds : 0.125, 0.25, 0.5, 1.0, 2.0, 4.0, 8.0, 12.0, 16.0, 20.0,
24.0, 32.0 and 48.0 mmScores
frequency bias Equitable Threat Score (ETS) log-odds ratio Extreme Dependency Score
00 UTC run of each model since the beginning of January 2004Means, timeseries & ascii contingency tables
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New (draft) proposal – later staged aims
2. Add higher resolution forecasts to intercomparison
3. Methods/code for high resolution forecasts Collaborate on investigation of new methods Intercomparison studies for set of forecasts from
single model(s) (cf NCAR project with WRF) Provide code for new methods Enable access to radar composites (OPERA)
4. Non-GTS data & hub Much greater financial and staff resources
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Why new draft may be acceptable
Practical & pragmaticStage 1 does not involve large cost or require extensive code changes
Stage 1 addresses primary concern (of EUMETNET directors) for meaningful verification of operational models
Stage 2 addresses new challenge of high resolution – still active research topic
Stage 3 will be necessary to evaluate and assess future operational high resolution models