Entering the pre-monsoon period, the city has already received irregular showers, may receive more in the coming days, said Pradeep John, a popular weather blogger who runs the Facebook Page Tamil Nadu Weatherman. Analysing past data and current global weather parameters, he said there was high chance that the monsoons this year would be favourable across the state.
“Madden Julian Oscillation (MJO), best described as intra-seasonal tropical climate variability, has been prolonged in November. Though weak in amplitude, MJO is coming into our basin in 2020 by the first or second week of November. The presence of MJO is enough for enhanced rains and not be in higher amplitude,” he said in a social media post.
Officials from the Regional Meterological Centre, Chennai, said that the La Nina movement in Pacific Ocean has led to a continuance of the southwest monsoon. “Right now there are repeated depressions in Bay of Bengal, which could move towards north of south India. Due to this, the northwardly winds may prevail in Tamil Nadu, Andhra Pradesh, south Karnataka and Kerala until October 22. Therefore, the northeast monsoon is expected to set in after October 25,” said S Balachandran, director, RMC.
However, after analysing data over the last 20 years, John said that while the monsoon could be delayed, this might work favourably for the state. “On-time onset has been a curse for Chennai resulting in eight years of failed rains. If the onset happened before October 15, most of the time it ended in excess. Over three years of delayed monsoon onset, we have ended in excess, with the last great flood on 2015 that was also a delayed onset. There is no fool-proof correlation and one can’t be sure to predict monsoon with onset dates,” he added.