Monsoon Onset Over Kerala Likely To Be Delayed, Says IMD; Check Expected Date

The onset of monsoon over Kerala is likely to be slightly delayed this year, the Indian Meteorological Department (IMD) said on Tuesday. The IMD has predicted the arrival of southwest monsoon on June 4 with a model arror of +- 4 days.

"India Meteorological Department (IMD) has been issuing operational forecasts for the date of monsoon onset over Kerala from 2005 onwards. An indigenously developed state of the art statistical model with a model error of ± 4 days is used for the purpose," IMD stated in an official press release.

"The 6 Predictors used in the models are; i) Minimum Temperatures over Northwest India ii) Pre-monsoon rainfall peak over south Peninsula iii) Outgoing Longwave Radiation (OLR) over south China Sea (iv) Lower tropospheric zonal wind over Southeast Indian Ocean (v) Mean sea level pressure over Subtropical NW Pacific Ocean (vi) Upper tropospheric zonal wind over North East Indian Ocean," the release said.

IMD’s operational forecasts of the date of monsoon onset over Kerala during the past 18 years (2005-2022) were proved to be correct except in 2015.

Forecast verification for the recent 5 years (2018-2022) is given in the table below.