The India Meteorological Department’s drought indicator has revealed that significant parts of India are currently experiencing mild to moderately dry conditions.
Following the driest August ever recorded, weather experts anticipate a brief resurgence of the southwest monsoon for 2-3 days this week, followed by a subsequent weakening.
As of Sunday, there is an 11% deficit in monsoon rainfall across the country, with central India experiencing a 12% shortfall, the peninsula facing a 14% deficit, and the eastern and northeastern regions encountering an 18% deficiency. The India Meteorological Department’s drought indicator highlights that substantial portions of India are grappling with mild to moderately dry conditions.
August marked the driest and warmest month for the entire country since weather records began in 1901, with 20 break monsoon days observed, surpassing the previous record of 16 set in 2005 during a period of extremely weak monsoons.
Recent data from the Meteorological Department indicates a gradual increase in break monsoon days over the years. In 2005, these days accounted for a 25% deficit in August, while this year, the figure stands at 36%.
The Meteorological Bureau reported on Sunday that a cyclonic circulation is forming over the northeast Bay of Bengal, likely leading to the development of a low-pressure area over the northwest and adjacent west-central Bay of Bengal in the next 48 hours. Furthermore, the monsoon trough, a long low-pressure area, continues along the Himalayan foothills. It is expected to shift southwards to its normal position, resulting in active monsoon conditions over northern peninsular India, Odisha, and Chhattisgarh over the next 2-3 days. An increase in rainfall, including isolated heavy rain, is anticipated over northeastern India, Madhya Pradesh, and Maharashtra starting from September 5.
Roxy Mathew Koll, a climate scientist at the Indian Institute of Tropical Meteorology, noted that prior to 2016, the 11% monsoon rainfall deficit would have been classified as an all-India drought. However, the nomenclature was changed in 2016, with rainfall between 96% and 104% of the long-period average considered normal, while 90% to 95% is deemed below normal, and less than 90% is considered deficient.
The Standardized Precipitation Index (SPI) is the widely used indicator for detecting meteorological droughts worldwide. It relies on precipitation data to assess wet or dry conditions and reflects soil moisture and rainfall conditions for specific locations.
Koll pointed out that the rainfall deficit pattern in 2023 aligns with the long-term declining trend of the monsoon, which is attributed to El Niño and Indian Ocean warming. A 2015 paper led by the Indian Institute of Tropical Meteorology found a significant weakening trend in summer rainfall from 1901 to 2012 in central-eastern and northern regions of India, affecting areas such as the Ganges-Brahmaputra-Meghna basin and the Himalayan foothills, where agriculture primarily relies on rainfall. The paper suggested that warming in the Indian Ocean weakens the land-sea thermal contrast, dampening the summer monsoon circulation and reducing rainfall in parts of South Asia.
Mahesh Palawat, Vice-President of Climate and Meteorology at Skymet Weather Services, a private forecaster, indicated that there would be rainfall in certain regions over the next 2-3 days, including Bihar, Jharkhand, West Bengal, Odisha, east Uttar Pradesh, and Chhattisgarh. However, after this spell, the monsoon is expected to move towards the withdrawal phase, with no significant rainfall activity anticipated thereafter.
M. Rajeevan, former secretary of the ministry of earth sciences, noted that while the favorable phase of the Madden Julian oscillation may support the monsoon in the first half of September, conditions are not favorable beyond that period. He also emphasized that nearly 40% of districts are currently classified as deficient, suggesting unfavorable conditions in many areas. Nevertheless, he anticipates improvement, especially in central and northern regions, with the possibility of an active monsoon spell in central India during the next 10 days, although a weaker spell might be expected in the latter half of September.
The Meteorological Office announced the likelihood of isolated very heavy rainfall over coastal Andhra Pradesh on September 4-5, along with light to moderate and widespread rainfall, thunderstorms, and isolated heavy rainfall forecast for various regions in central India during specific periods in early September.
