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The extended range (monthly) ensemble is run daily based on 00UTC data.  The products cover the period up to Day46 and are derived from a 100 member ensemble with a control and has a resolution of 36km.   The extended range ENS is independent of the medium range ENS and has it's own control and extended range model climate (ER-M-climate).

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After about 10 days of forecasts, the spread of the ensemble can become very large.  A significant shift can be detected by comparing probability distribution functions of the latest model and the ER-M-climate.

The re-forecasts are created twice a week (Mondays and Thursdays) and are ready a week before the real-time forecasting suite starts.  Real-time forecasts are calibrated using all the re-forecasts available in a one week window centred on the forecast start day and month. ?????

Fig5.2.1: Example of plumes for Dublin.  Extended Range forecast, DT00UTC 1 January 2018.  The plumes show increasing spread of forecasted values of 850hPa temperatures and 500hPa geopotential height within the extended range period.

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