The Dilemma of Seasonal Monsoon Prediction (Invited Presentation)

The monsoon systems, especially those associated with Asia, have long been known to affect the lives of a large proportion of humankind. One of the great challenges, largely unmet, has been the forecasting of the seasonal variability of the monsoon rains with sufficient lead-time to allow mitigatory actions to be taken. Short-term forecasts of monsoon weather on the scale of 1-10 days, including those associated with hazardous events, have shown a persistent increase in predictive skill. The physics of bi-weekly variability and longer intraseasonal variations of the monsoon are now more fully understood perhaps portending at least useful empirical forecasts. Yet, despite intense efforts for nearly 100 years, seasonal forecast skill has remained relatively poor. We examine the degree of complexity of the monsoon system and the interplay of other major low-frequency climate phenomena and the often-complicated lag-lead relationships.

We attempt to ascertain the degree of predictability of the monsoon and question whether or not we can expect systematic forecasts to evolve and, if not, are there adaptive strategies nations in the monsoon region can adopt to deal with non-predictive inherent variability.