Bhubaneswar: The wait for southwest monsoon over Kerala is likely to be delayed as compared to the normal onset date. As per India Meteorological Department (IMD), the monsoon onset over Kerala this year is likely to be on June 5 with a model error of ± 4 days.
Normally, the southwest monsoon sets over Kerala on June 1 with a standard deviation of about seven days. The advancement of the southwest monsoon over Indian mainland is usually marked by monsoon onset over Kerala.
In April, IMD had said that the chances for a normal monsoon are high (41 per cent) and chances for above-normal monsoon are 21 per cent.
As per the latest IMD forecast, monsoon will advance over the Andaman Sea around May 22 as a well-marked Low-Pressure Area lies over southeast Bay of Bengal & neighbourhood. It is very likely to concentrate into a Depression over the same region during next 12 hours. The system is likely to further intensify into a cyclonic storm over central parts of south Bay of Bengal by May 16 evening.
Such conditions are likely to become favorable for advance of Southwest monsoon into Andaman Sea, Andaman & Nicobar Islands and some parts of southeast Bay of Bengal during the next 48 hours. However, past data suggest that there is no association of the date of monsoon advance over the Andaman Sea either with the date of monsoon onset over Kerala or with the seasonal monsoon rainfall over the country.
IMD uses state of the art statistical model with six predictors-minimum temperature over North-west 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, outgoing long wave radiation (OLR) over the south-west Pacific region for monsoon forecast.