| Implementation date | 8 Dec 2014 |
| Detailed description of changes | See below |
| Resolution | Unchanged |
| Data set affected | ENS |
| Meteorological changes | Addition of new clusters |
Previously
| Added
|
| Meteorological impacts | |
| Technical changes | Availability in dissemination and MARS |
| New disseminated model output | Additional clusterings |
| Discontinued disseminated model output | None |
ECMWF cluster products have been updated on 8 December 2014
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Cluster products have been produced operationally since 1992. However in November 2010 new cluster products were introduced in order to provide an effective framework to construct a flow dependent verification, and to extend the products to different forecast ranges (for more details see ECMWF Newsletter N.127 (Spring 2011, pp 6-11)
The clustering algorithm takes the 51 forecasts (50 perturbed plus 1 control forecast) and groups together those that show a similar evolution of the 500 hPa geopotential over the North Atlantic and Europe (75°N–30°N, 20°W–40°E). For two Ensemble members to join the same cluster they must display similar synoptic development at 500 hPa throughout a given time window. Clustering in this way, rather than on individual forecast days, has the advantage that temporal continuity and synoptic consistency are retained. The clustering is made independently for four time windows:
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For questions related to the Cluster products, please contact us (Subject="Scientific or technical question about data")
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