THIRUVANANTHAPURAM: Rain clouds finally made their way to the Kerala coast on Wednesday, heralding the onset of the southwest monsoon in the country. The India Meteorological Department (IMD) is expected to make an official announcement soon.
Meteorological indicators, such as the persistence of westerly winds over the south Arabian Sea, an increase in the depth of westerly winds in the middle troposphere, and enhanced cloudiness in the southeast Arabian Sea, Lakshadweep, and Kerala coasts, have created favourable conditions for monsoon onset.
“Under such a scenario, the conditions are becoming favourable for monsoon onset over Kerala during the next 48 hours,” the IMD said on Wednesday.
The monsoon’s soft launch was attributed to the presence of an uncommon cyclonic system that developed in the Arabian Sea during the season. However, the cyclonic storm, christened Biparjoy, moved further northwards strengthening the monsoon winds and creating favourable conditions for the rainy season, explained weather experts.
Rain to pick up in 2 days, says weather expert
For all intents and purposes, monsoon has arrived. After the progression of Biparjoy, westerly winds have picked up strength to move the clouds and spread it across,” said Rajeevan Erikkulam, meteorologist of Kerala State Disaster Management Authority (KSDMA).
“The rainfall will pick up in two days. However, it will acquire full strength only after the cyclone’s influence weakens further,” he said.
IMD can declare monsoon onset upon fulfilment of four meteorological conditions. Experts said it has become increasingly difficult to align.
The rainfall criteria, the most visible manifestation of monsoon arrival, can be met only when 60% of IMD’s 14 stations record rainfall of 2.5mm or more on two successive days. The latest recording showed only seven stations met the criteria.
The IMD had announced the date of onset as June 4, with a model error of four days. This means that even if the official announcement is made by June 8, the forecast will be considered accurate.
Private forecaster Skymet had predicted the onset on June 7. IMD has been issuing operational forecasts for the monsoon onset date in Kerala since 2005. Barring 2015, its predictions in the past 18 years have proven correct.