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The plot below shows the evolution of forecasts of 3-day accumulated rainfall in Ratnapura valid 24-26 May. The blue box-and-whisker shows the ensemble distribution, the red dot the HRES forecast and the red box-and-whisker the climate distribution based on re-forecasts. The observed value was 535 mm, which is actually inside the ensemble distribution of the last forecast. Already the forecasts from 12 days before the event predicted a wet anomaly, but the uncertainty was large also for the shortest forecasts.
3.4 Monthly forecasts
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- The short and medium-range forecasts clearly underestimated the precipitation on 24-26 May, but the outcome was covered in the ensemble distribution from the last forecast.
- Some signal in monthly forecasts (connected to MJO?)
- Weak signal in EFI, due to "extreme" climatology
- Observations missing from Sri Lanka in our system but available on the web
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