Goemkarponn Desk
PANAJI: The southwest monsoon is expected to set in over Kerala around May 31, marking the onset of the rainy season, as per the current climatic predictors, the India Meteorological Department (IMD) announced on Wednesday.
The actual onset could happen between May 27 and June 4, the weather department said. The southwest monsoon normally sets in over Kerala on June 1 with a standard deviation of about seven days.
“This year, the southwest monsoon is likely to set over Kerala to be on 31st May with a model error of +/- 4 days,” the weather agency said in its latest forecast.
IMD Director General Mrutyunjay Mohapatra noted, “This is not early. It’s near normal date as the normal date for onset of monsoon over Kerala is June 1,”
The southwest monsoon, a seasonal wind pattern that brings vital rainfall to India is critical to India’s agriculture, as it provides the majority of the country’s annual rainfall. June and July are considered the most important monsoon months for agriculture as most of the sowing for the Kharif crop takes place in this period.
The monsoon blows from the southwest, typically arriving in Kerala around the beginning of June and retreating by the end of September. According to IMD, this year, above-normal rainfall is expected during the monsoon season.
Last year, the onset of monsoon was marked on June 8, with a four-day delay from the predicted date.
“Advance of the monsoon over Indian mainland is marked by monsoon onset over Kerala and is an important indicator characterising the transition from hot and dry season to a rainy season,” IMD said.
As the monsoon progresses northward, relief from scorching summer temperatures is experienced over the areas. IMD has been issuing operational forecasts for the date of monsoon onset over Kerala from 2005 onwards, based on a statistical model.
The six predictors used in the models are — 1) Minimum Temperatures over north-west India, 2) Pre-monsoon rainfall peak over south Peninsula, 3) Outgoing long wave radiation (OLR) over south China Sea, 4) Lower tropospheric zonal wind over equatorial south-east Indian Ocean, 5) Outgoing OLR over south-west Pacific Ocean and 6) Upper tropospheric zonal wind over equatorial north-east Indian Ocean, IMD said.
