...
The plot below below shows the weekly mean precipitation anomaly for 25 December - 31 December. All lead-times here showed a wet anomaly around 10-15N, and the forecast from 16 Decmber had already a very strong anomaly.
Also the seasonal forecast from 1 November predicted a wet season for the region around the Maldives.
The plot below shows MJO forecasts from 31 December and 26 December. A strong MJO event was present in the western Indian Ocean around the day of the extreme.
...