On forecasting the Indian summer monsoon: the intriguing season of 2002

Abstract

This year, the rainfall over India during the first half of the summer monsoon season was 30% below normal. This has naturally led to a lot of concern and speculation about the causes. We have shown that the deficit in rainfall is a part of the natural variability. Analysis of the past data suggests that there is a 78% chance that seasonal mean rainfall this year will be 10% or more below the long-term average value. We discuss briefly how forecasts for seasonal rainfall are generated, whether this event could have been foreseen, and share our perspective on the problems and prospects of forecasting the summer monsoon rainfall over the Indian region.