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Differences can be seen in the depth and timing of the upper trough near Scotland at T+120 and the building of the following upper ridge towards southwest Britain.  However, overall the differences between the three clusters do not look to be particularly large on this occasion.

The web site includes cluster products equivalent to Fig8.1.3.2 for each of the four predefined lead-time windows.  For additional information, the 1000hPa geopotential fields are also provided for each ensemble scenario to show the corresponding near-surface evolution.  Users should note that for these the clustering has been made on the 500hPa fields, not the 1000hPa fields.  Whilst the user should not treat the most representative members as deterministic solutions, it can nonetheless be helpful to examine the details of the evolution in such members, to see how a particular scenario can plausibly arise and evolve.  One good way to do this is to use the cyclone database products presented by the extratropical cyclone diagrams, specifically the animations, at 12 hour intervals, of synoptic patterns for individual members.

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