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Adjacent to each EFI chart is a duplicate chart showing a user-selectable quantile of the M-Climate for the same quantity.  Quantiles available are:

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Colours indicate the quintile90 temperature ranges of the M-climate where only one in 10 occasions have reached greater values than shown (i.e. on only 1 in 10 occasions during the construction of M-climate for each location and on this date have the temperatures indicated by the colours been exceeded).  The chart shows on only 1 in 10 occasions are mean temperatures likely to be above 15°C-20°C in parts of southern Italy and Sicily.  The high EFI and locally positive SOT in these areas suggests unusually high mean temperatures may be expected.  Selection of quintile10 would allow a similar assessment of how unusually cold the mean temperature in Portugal is likely to be.

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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 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.

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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 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.

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Fig8.1.9.7-6: CDF and associated EFI for NW Portugal area.  There is a consistently high and increasing EFI for rainfall (reaching 80%) which is sufficient for forecasting a significant and maybe an extreme rainfall event.  Some ensemble members show rainfall totals much greater than M-climate maxima - the degree to which these totals exceed the M-climate maximum is not taken account of in the EFI calculation, but is used directly in calculating SOT.  The EFI for maximum wind gust is greater than 50% in the last two forecasts but this is not really sufficient for forecasting a significant wind event. The steep and consistent temperature CDF indicates high confidence in a forecast of near normal temperatures around 14°C.  

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 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.

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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 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.

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Fig8.1.9.7-8: CDF and associated EFI for Marseilles area.  There is a consistently high and increasing EFI for wind (reaching 86%) which is sufficient for forecasting a significant and possibly extreme wind event.  The CDF shows consistency between the stronger gust forecasts in last two ensemble results.   Some ensemble members show wind gusts much greater than M-climate maxima - the degree to which these values exceed the M-climate maximum is not taken account of in the EFI calculation, but is used in calculating SOT.  The steep and consistent mean temperature CDF indicates high confidence in a forecast of near normal temperatures around 16°C.  

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 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.

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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 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.

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The development and evolution of EFI and SOT over a sequence of charts can give an early insight into the likelihood of occurrence of out-of-the-ordinary weather and the confidence that may be assigned to developments.  EFI values roughly indicate the extent to which ensemble members forecast values exceed the corresponding M-climate.  At longer lead-times the number of such members may be quite low. However areas of SOT >1 on longer lead charts give an indication that at least some ensemble members are showing extreme values.  This shows there is a risk, albeit small, of out-of-the-ordinary weather within the marked area.  As the forecast lead time shortens, EFI values will indicate any increase or decrease in the number of members exceeding the corresponding M-climate value.  At the same time the isopleths of SOT will show the variation in the potential for extreme values and give an increasing definition of the risk area (if there is one!).

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Fig8.1.9.7-10: An example of the use of EFI and SOT during the period leading up to 05-06 September 2018.  The evolution of this sequence illustrates the ability of EFI and SOT charts to allow early indication the risk of severe weather (SOT), with an indication of changes in confidence and definition of the area at risk (EFI).  EFI tends to be greater than 0.5 if the majority of ensemble member forecast values are markedly greater than those of the corresponding M-climate.  EFI>0.5 is coloured (see scales). SOT>0 if at least 10% of ensemble members forecast an extreme event.  Isopleths are for values of 0,1,2,5,8.  The actual SOT values show how extreme the top 10% of ensemble forecast are:

Chart A (from a forecast 6 days ahead of the event) shows fragmented areas where SOT>0 (i.e. a few ensemble members show an extreme event) so a very severe weather event is possible.  However, generally low EFI values (<0.5) shows the majority of ensemble members do not indicate an unusual event (even though a few do).

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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 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.

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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 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.

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Fig8.1.9.17-13:  Extreme Forecast Index for total precipitation during the 10 day period 00UTC 10 Apr 2023 to 00UTC 20 Apr 2023.   The forecast cumulative distribution function (CDF) suggests that during the period there is less than 10% probability of below 35mm precipitation, 90% probability of below 80mm precipitation, and 10% probability of greater than 80mm.  The forecast CDF (red) is well above the M-climate CDF (black) and shift of tails values are quite high.  For a desert region, quite moderate precipitation values can be devastating.  

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 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.

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An example of high probability of an unusual event.  Very calm sea in the Mediterranean.

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Fig8.1.9.17-14: An example of a forecast of exceptionally calm conditions in the Mediterranean.  The chart shows extreme forecast index (EFI) for wave height during the 24 hour period 00UTC 10 Apr 2023 to 00UTC 11 Apr 2023.  The colours on the cumulative frequency diagram show the results from the most recent ensemble runs; red is the latest.  The forecast cumulative distribution functions (CDF) of the last few runs suggest strongly that wave heights will be only just a few cm.  The forecast CDF (red) is well below the M-climate CDF (black) and EFI values are strongly negative.  

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 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.

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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 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.

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