“The long-range forecast of the onset and withdrawal dates of monsoon rainfall is critical for taking appropriate decisions at various levels, from farmer’s field to the central government,” says Surovyatkina. “When to plow and seed, but also how to manage water resources and design food procurement policies - in India, all this depends on the Monsoon. We’re therefore glad to complement forecasts by the Indian authorities.”
Although the rainy season happens annually between June and September, the time of monsoon season’s onset and withdrawal varies within a month from year to year. “The important feature of the monsoon is that it starts and ends suddenly. Hence, forecasting it remains a significant scientific challenge," says Surovyatkina. "However, this helped me to realize that the sudden onset of monsoon means a threshold behavior, and inspired me to apply the theory of critical transition for a prediction of monsoon.”
The long-term forecast means 40 days in advance for the onset date, and 70 days in advance for the withdrawal date. The prognosis will be provided yearly before and during Monsoon season. Local events such as a pair cyclones from both sides of Indian subcontinent can stop monsoon for a week. Such random events are unpredictable. In such cases, the forecast will be updated. A forecast for the monsoon withdrawal will be issued on 27 July.
Weblink to the PIK monsoon page with more detailed information: https://www.pik-potsdam.de/services/infodesk/forecasting-indian-monsoon
