Page History

Note: HRES and Ensemble Control Forecast (ex-HRES) are scientifically, structurally and computationally identical.  With effect from Cy49r1, Ensemble Control Forecast (ex-HRES) output is equivalent to HRES output shown in the diagrams.   At the time of the diagrams, HRES had resolution of 9km and ensemble members had a resolution of 18km.

At inception around 2010, the extra-tropical cyclone diagrams (= "cyclone database" products) were generated using bitmap manipulation. As a result the products had a somewhat noisy/jagged visual appearance relative to many NWP products available nowadays (2021). In addition the software was proving costly to maintain. So in May 2021, and in close collaboration with the UK Met Office, ECMWF upgraded to a Python-based code suite, which applies the same graphical processing principles, but which saves the frontal objects in vector form and recreates fronts from those vectors wherever they are needed on a product. For these products this provides an aesthetically pleasing visual appearance, clearer rendering of details and a capacity to use transparency settings. In future this software change will also facilitate greater platform portability (e.g. for ecCharts, commensurate with user requests) and easier development of other product variants. During the upgrade a few other minor changes were applied, including correction of a pre-existing bug that affected the strike probability products. The main differences in output that resulted from these various changes are highlighted below, for user reference:

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See the new Cyclone Database Products.

(FUG Associated with Cy49r1)