BENGALURU: The India Meteorological Department (IMD) forecasts a delay in the onset of the much-awaited southwest monsoon. Instead of its usual arrival on June 1, it is likely to hit the Kerala coast on June 5, with a model error of an advance or delay of four days.
Weathermen say that normally, the southwest monsoon sets over Kerala on June 1, with a standard deviation of about seven days. The initial monsoon rain is experienced over South Andaman Sea and monsoon winds then advance northwest across the Bay of Bengal, say officials. But as per the Met update, the monsoon will advance over the Andaman Sea around May 22.
At present, there is a well-marked low-pressure area over southeast Bay of Bengal and in neighbouring regions. It is likely to concentrate into a depression and further intensify into a cyclonic storm over central parts of south Bay of Bengal.
The IMD uses six predictor models to forecast southwest monsoon – minimum temperatures over Northwest India, pre-monsoon rainfall peak over South Peninsula, outgoing long-wave radiation (OLR) over South China Sea, lower tropospheric zonal wind over southeast Indian Ocean, upper tropospheric zonal wind over the east equatorial Indian Ocean, and OLR over the Southwest Pacific region.