New Delhi (NVI): This year, the onset of southwest monsoon over Kerala is likely to be slightly delayed as compared to normal date of onset of 1st June, the India Meteorological Department said today.
The monsoon onset over Kerala this year is likely to be on 5th June with a model error of ± 4 days, IMD said.
The advance of the southwest monsoon over Indian main land is marked by monsoon onset over Kerala and is an important indicator characterizing the transition from hot and dry season to a rainy season, the Ministry of Earth Science said, while giving the background of the weather phenomenon.
As the monsoon progresses northward, relief from scorching summer temperatures is experienced over the areas. Southwest monsoon sets over Kerala on 1st June with a standard deviation of about 7 days, it said.
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, the Ministry added.
The 6 Predictors used in the models are; i) Minimum Temperatures over North-west India, ii) Pre monsoon rainfall peak over south Peninsula, iii) Outgoing Long wave Radiation (OLR) over south China Sea, (iv) Lower tropospheric zonal wind over southeast Indian Ocean, (v) upper tropospheric zonal wind over the east equatorial Indian Ocean, and (vi) Outgoing Long wave Radiation (OLR) over the south-west Pacific region.
IMD’s operational forecasts of the date of monsoon onset over Kerala during the past 15 years (2005-2019) were proved to be correct except in 2015, the Ministry said.
