The onset of Southwest Monsoon 2017 over Kerala is likely to be on May 30, with a model error of 4 days, the India Meteorological Department (IMD) said on Tuesday.
The statement, issued by the IMD office in Thiruvananthapuram, said that the onset of Southwest Monsoon over Kerala signals the arrival of monsoon over the Indian subcontinent and beginning of rainy season over the region.
The date of the normal monsoon onset over Kerala is June 1 and since 2005, the IMD started to issue operational forecasts for the date of monsoon onset over Kerala.
"For this an indigenously developed statistical model with a model error of 4 days is used. The model uses the following six predictors which includes minimum temperatures over northwest India, pre-monsoon rainfall peak over south peninsula, outgoing long wave radiation over south China Sea, lower tropospheric zonal wind over southeast Indian Ocean, upper tropospheric zonal wind over the east equatorial Indian Ocean, and outgoing long wave radiation over the south-west Pacific region," said the statement.
The forecasts of the monsoon onset issued during the past 12 years (2005-2016) were proved to be correct for all years except 2015.