After a wet August, IMD says Sept to be rainy too
The month follows what was a wetter-than-normal August, which received 16% more rain than the average
India is in for a rainier-than-normal September, with heavy to very heavy spells that could hit the northwest region, the India Meteorological Department (IMD) said on Saturday, with its chief warning of “flash floods, landslides, mudslides, and landslips” in some regions.
The month follows what was a wetter-than-normal August, which received 16% more rain than the average.
IMD director general M Mohapatra said models indicate “a low-pressure system developing over the Bay of Bengal each week of the month, which will result in significant rainfall across the country”.
IMD’s data also revealed that it was the warmest ever August for the country in terms of aggregate night-time or minimum temperatures, which it attributed to extensive cloud cover during the month that did not allow heat to escape.
For the month beginning Sunday, Mohapatra, addressing an online press briefing, identified the regions of Uttarakhand, parts of Himachal Pradesh, Jammu and Kashmir, Rajasthan, and the adjoining areas of Madhya Pradesh as being cause of concern.
“There could be episodes of extremely heavy rainfall in these areas, potentially leading to floods. We should remain cautious of landslides, mudslides, and landslips,” Mohapatra said.
The agency in its forecast said rain for September 2024 over the country as a whole is most likely to be above normal (>109 % of the Long Period Average, or LPA).
Taking into account the wet August, if the rains in September track the latest forecasts, the second half of the monsoon season could record excess rains in what will be encouraging for India’s farm sector and the broader economy.
Agriculture accounts for 18-20% of the GDP, and at least half of the net sown area is rainfed, making the country’s economic output sensitive to the monsoon season. Data released on Friday showed the economy grew at 6.7% in the quarter ending June, the slowest rate in five quarters.
The LPA over the country during September, based on data from 1971-2020, is about 167.9 mm.
The government weather forecaster also said September will be warmer than usual with above-normal maximum temperatures in most parts of the country, except for some areas in northwest India, south peninsular India, and some pockets of east-central India, where normal to below-normal maximum temperatures are likely.
Above-normal minimum temperatures are also likely over most parts of the country, except for some isolated pockets of northwest India, foothills of Himalayas and south Peninsular India, where normal to below normal minimum temperatures are likely.
Current conditions over the equatorial pacific show an ENSO-neutral state, meaning the El Nino – a condition that saps the monsoon season of rains in India --- has abated, but forecasts suggest a higher probability of La Niña (a phenomenon that leads to more monsoon showers in India) taking hold towards the of the monsoon season, which culminates with the end of September.
The Indian Ocean Dipole (IOD) is presently neutral and is predicted to remain so through the remainder of the monsoon period.
Mohapatra said the month of August recorded approximately 16% more rainfall than normal. India received 287.1 mm of rainfall in August, compared to the normal 248.1 mm.
Overall for this monsoon season (the period beginning June 1), there is 7% excess rain with a 20% excess over South Peninsula; 13% deficiency over east and northeast India; 17% excess over central India; 2% excess over northwest India.
Some regions, including the foothills of the Himalayas and parts of northeast India, experienced below-normal rainfall due to the southward movement of low-pressure systems and the monsoon trough, two atmospheric zones that influence precipitation.
The IMD reported that the deep depression over the Arabian Sea, now Cyclone Asna, is expected to move west-northwest over the northeast Arabian Sea and away from the Indian coast within the next 24 hours. “Cyclone Asna intensified into a cyclone storm by noon on August 30 and is forecasted to weaken to a depression or low-pressure area by September 1 as it approaches the Oman coast,” said Mohapatra.
Heavy rainfall has been reported in Kutch, Gujarat, due to Cyclone Asna. The IMD has forecasted very heavy rainfall at isolated places in Odisha, Chhattisgarh, Coastal Andhra Pradesh, Yanam, and Coastal Karnataka over the next seven days.
Heavy rainfall is also expected in Central India, Kerala, Mahe district of Puducherry, Coastal Karnataka, and Central Maharashtra during this period.
Mohapatra also said that a new depression formed in the Bay of Bengal on the morning of August 31 and is forecasted to affect north Andhra Pradesh and south Odisha coasts around midnight, bringing 45 to 60 mph winds and heavy rainfall.
The IMD chief said that six low-pressure systems formed in August, two of which intensified into monsoon depression or deep depression. Mohapatra said, “There were 17 low-pressure system days this August, compared to the normal of 16.3 days.”