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The plot below shows ensemble forecasts for week 27 averaged in the box 40-50N, 0-10E
. From 25 June and onwards the forecast has been very consistent, and the strong signal for the heatwave was predicted already on 22 June. The monthly forecast from 18 June was also for warmer than normal but not the one from 15 June. The z500 anomaly in the ensemble mean pattern over the Euro-Atlantic in the forecast from 18 June has the same structure as the current structure (Atlantic trough and European ridge). This was not the case for the forecast from 11 June that anyway had a warm anomaly for Western Europe.
3.5 Comparison with other centres
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