Monsoon arrives three days ahead of time in Kerala
Some experts said IMD may have shown haste in announcing the arrival as the rainfall criterion for the onset of monsoon remained unmet on Sunday.
The southwest monsoon has arrived in Kerala three days ahead of its usual schedule of June 1, the India Meteorological Department said on Sunday, although its progress could be slow, at least in the initial days.
This was the third announcement by the weather office regarding the onset of the June-to-September season that is vital for India’s autumn harvest, besides bringing rain relief from the high summer temperatures.
On May 14, the department predicted that monsoon was likely to make landfall over Kerala on May 27, five days ahead of its normal onset date. On Friday, it said there could be a delay of 2-3 days due to a weakening of south-westerly winds. Its extended range forecast also indicated weak rainfall over most of the country, except northeast India, from June 2 to 8.
“We had said monsoon onset is likely on May 27 with an error margin of +/-4 days. This is not a linear science and an error margin is maintained the world over,” director general M Mohapatra said. “A probability can be given, but not always accurate dates.”
Some experts said IMD may have shown haste in announcing the arrival as the rainfall criterion for the onset of monsoon remained unmet on Sunday.
“It’s correct that the rainfall criterion was met for 24 hours, and not for two days, but most monsoon criteria were met so onset can be announced,” Mohapatra said.
The weather bureau declares the arrival of the southwest monsoon only after at least 60% of 14 weather stations in Lakshadweep and coastal Kerala report rainfall of 2.5mm or more for two consecutive days after May 10.
The depth of westerly winds had increased and there has been widespread rainfall over Kerala in past 24 hours, IMD said on Sunday.
“Monsoon progress may be slow. There is a cyclonic circulation over Kerala, which may help to advance it for next 2-3 days,” the government’s chief meteorologist said. “We have mentioned that in our forecast.”
“The monsoon flow has weakened and further monsoon progress could be slow,” said M Rajeevan, former secretary at the ministry of earth sciences. “At least for the next one week, monsoon could be weak and not much rainfall can be expected.”
A long dry spell and severe heatwaves over northwest and central India in March through May affected the wheat harvest in many parts, fuelling a rise in food prices. The monsoon, which is supposed to begin on June 1, is crucial for summer crops, as 60% of the country’s cultivated area is not irrigated. It brings about 70% of India’s annual rainfall.
There was likely to be a gradual rise in maximum temperatures by 2-4 degrees Celsius over many parts of northwest India in the next three days and over eastern India in the next five days, the weather bureau predicted.
“Monsoon onset is predicted as per the present scenario and how they will pan out in the next 14 to 15 days. I think IMD has announced monsoon onset slightly prematurely,” said Mahesh Palawat, vice president of climate change and meteorology at Skymet Weather, a private forecaster.
The monsoon surge will not be very good, he added. “There is likely to be light to moderate rainfall over Kerala and Karnataka for a week, but not active monsoon conditions,” Palawat predicted.
“#Monsoon2022 reached #Kerala on 29 May. Slow advance is expected over the next few days with monsoon possibly reaching #Mumbai during the week of 6 June. Onset in #Odisha & #WestBengal possible around the 10th,” tweeted Jason Nicholls, forecasting manager at AccuWeather, a private weather prediction company.
Conditions were favourable for the further advance of the monsoon into inland Kerala, and some parts of Tamil Nadu, Karnataka and the northeastern states in the next three to four days, IMD said on Sunday.
“The official short-term forecast issued on May 28 suggested that the monsoon would reach Kerala during May 30-31. This forecast was logical and supported by weather models, which are consistently predicting the strengthening of the monsoon in the Lakshadweep-Maldives region and subsequent onset of the monsoon in Kerala between May 30 and June 2,” said Akshay Deoras, an independent meteorologist and doctoral researcher at the UK’s University of Reading. “Hence, the declaration of the onset on May 29 was surprising. The onset might have been declared under the assumption that the rainfall condition would continue to satisfied on May 29.”