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| Titel |
Development of an ensemble forecasting system for the short-range following different perturbation approaches. |
| VerfasserIn |
Chiara Marsigli, Andrea Montani, Tiziana Paccagnella |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250054944
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| Zusammenfassung |
| Short-range ensemble forecasting is nowadays among the operational practice of many Weather Centres.
At ARPA-SIMC, the operational ensemble COSMO-LEPS has been recently joined by the experimental COSMO-SREPS system, more tailored for the short-range. Both systems are based on the COSMO model and run at 7 km horizontal mesh-size, but are designed for different forecast ranges (day 3-5 and 1-2, respectively) and with different perturbation strategies. COSMO-LEPS performs a dynamical downscaling of the ECMWF EPS, while COSMO-SREPS receives initial and boundary conditions by a few state-of-the art operational deterministic runs (IFS, GME, GFS), following a multi-analysis multi-boundary approach. Both systems benefit of perturbations applied to the COSMO model itself.
In this work, the impact of the different perturbation strategies on short-range forecast skill is assessed, by performing a detailed intercomparison of the two systems for the first 2 forecast days. The relative importance of initial state and boundary perturbations and of model perturbation is also shown. The behaviour of the perturbations is studied and a verification of the systems performance is undertaken. The impact of combining the two different ensembles for the aim of short-range forecasting is also assessed, tackling the relative importance of ensemble population and member diversity. |
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