After stalling for an abnormally long period of 11 days, monsoon has revived to spread into more parts of Central India and is expected to hit Delhi on June 29, its normal onset date for the national capital.
Conditions are becoming favourable for pre-monsoon thunderstorm activity over parts of northwest India from June 27, Indian Meteorological Department’s (IMD) Additional Director General Mritunjay Mohapatra said.
After making an early arrival on May 29 when it Kerala coast, three days ahead of its normal on-set date, the Southwest Monsoon covered the coastal parts of Kerala, Karnataka, Maharashtra and south Gujarat. After a fortnight, the system had remained stalled since June 12 for an unusually long period of 11 days due to unfavourable conditions in the Indian Ocean, from where the rain-laden winds originate. This has resulted in a countrywide rainfall deficit of 11%.
Reviving after the lull, the monsoon advanced into more parts of central India on Sunday. Met officials expect its progress to continue, with the rain-bearing system now looking likely to cover parts of north India, including Delhi, by June 29 to July 1.
Before that, pre-monsoon showers are expected in north India from Tuesday or Wednesday, which could be quite widespread.
“We expect good rainfall in the next few days that will hopefully wipe out much of the deficit by the end of this month,” said M Mohapatra, additional director-general, IMD.
The monsoon covers the entire country normally by the middle of July.
IMD expects a good monsoon in the crucial sowing month of July, during which it has forecast 101% rainfall (1 percentage point higher than normal) while the forecast for the entire June-September period is 97%, on the lower end of the normal range.
Its forecast along similar lines, Skymet weather also said isolated thunderstorm activity is expected to commence over Delhi and the NCR region around June 26. However, for the next 24 hours, heatwave like conditions will persist.
Thereafter, easterly winds will start moving towards Delhi and NCR along with the Northern Plains leading to the commencement of Pre-Monsoon activities around June 27.
Gradually, these Pre-Monsoon activities will start increasing. Thus, on and off rains will continue for some time. The normal date of arrival of monsoon over Delhi is around June 29 and we expect timely onset of monsoon over Delhi with an error margin of +/-2 days, said Skymet weather.
“Rains are expected to increase further, and we expect good rains around June 30 and 31st. In fact, the month of July is also expected to begin on a rainy note. In a nutshell, by the end of the month good rains will commence over Delhi and NCR leading to significant drop in temperatures as well,” reported Skymet weather.
The maximums are expected to drop down to around 35 and 36 degrees Celsius which at present are settling between 43 and 45 degrees. Thus, significant relief is expected in coming days as Southwest Monsoon will also make an onset over Delhi and NCR.
However, there are now growing fears of an El Nino forming during the last month of the monsoon season which could subdue rains during September, said a Times of India (TOI) report. El Nino is an abnormal warming of ocean waters in the east equatorial region of the Pacific, which often suppresses the southwest monsoon.
“There’s a good chance of El Nino forming this year. The higher uncertainty is about when it will set in. If it forms after September, the monsoon may not get impacted. If it happens earlier, we could see subdued rainfall in September. But that too will depend on other local factors,” said D Sivananda Pai, IMD’s lead monsoon forecaster, reported TOI.
The uncertainty over conditions during the second half of the monsoon season was one reason why IMD had pegged rains in August at 6% below normal in its updated monsoon forecast released earlier on May 30.
Meanwhile, IMD data has revealed that less than 25 per cent of the country received normal or excess rains till now, according to a report by news agency PTI.
The overall monsoon deficiency stood at minus 10 per cent.
Of the four meteorological divisions of the country, only the southern peninsula has recorded 29 per cent more rains. The rainfall deficit was 29 and 24 per cent in east-northeast and northwest India respectively.
Of the 36 meteorological sub-divisions in the country, 24 subdivisions have received ‘deficient’ and ‘largely deficient rainfall’. This means, less than 25 per cent of the country has received ‘normal’ or ‘excess’ rainfall.