Monsoon 2024 unlikely to bring relief to North East India as IMD forecast paints grim picture, dry trend to continue

The southwest monsoon 2024 is expected to bring good rainfall to most regions of India — with the notable exception of the northeastern states, according to the second long-range forecast for the season released by India Meteorological Department (IMD) May 27, 2024. 

North East India saw little rain in the pre-monsoon season as well. This trend of low monsoon rainfall has persisted in the region specifically for over two decades and generally throughout the past century.

Monsoon 2024 may be lean for Odisha, West Bengal, Himachal Pradesh and the Union territories of Jammu and Kashmir and Ladakh too. 

Rains brought by cyclone Remal at the end of May provided the only respite from the dryness and heat of the summer months in the northeastern region. Assam even experienced two heatwave days in May, a rare occurrence for the state. 

“There may be further rainfall from a western disturbance that is going to reach northeast region by May 31 and June 1,” said Mrutyunjay Mohapatra, director general of IMD, in a virtual press conference on May 27. 

Overall, India is expected to receive 106 per cent of the long period average (LPA) rainfall of 870 millimetres, according to IMD. LPA is the average rainfall during the monsoon between 1971 and 2020. 

The prediction is consistent with an earlier forecast made by IMD on April 15, 2024. 

But there is a good chance that rainfall in Northeast India will be less than 94 per cent of the LPA, which is classified as a below normal monsoon by the IMD. 

The chances of this forecast coming true are also fairly high. IMD has calculated that there is a 55 per cent chance that the forecast rainfall will be below normal. It says that there is a 39 per cent chance that the rainfall would be in the normal range (96-104 percent of the LPA) and only a six per cent chance that it would be above normal (over 106 per cent of the LPA).

Rainfall in June will be mostly limited to the southern parts of the country, while the rest of the country will experience deficit rainfall,according to the IMD forecast. This could continue the hot and dry conditions for many regions. 

The dry monsoon trend has been a long and slowly occurring catastrophe for northeastern states. In 18 of the last 19 years (2001-2019), the region received less than normal monsoon rainfall, with the exception of 2007 (110 per cent of normal), according to an IMD report from 2019.

This trend has continued in recent years, particularly in the states of Nagaland, Mizoram, Manipur, and Tripura, which are also classified as NMMT meteorological subdivisions by IMD. In 2021, the entire region suffered from a severe deficit in rainfall. In 2020, 2022 and 2023, the deficit rainfall was restricted to the NMMT region. 

Even longer-term trends paint a bleak picture for the region, foreshadowing a bleak future if it continues. For instance, a research paper published in the Hydrological Science Journal shows that from 1871 to 2005, the NMMT subdivision showed a decline in overall monsoon rainfall of 135 mm. This was the third highest after Chhattisgarh and Kerala. 

A monsoon rainfall analysis by IMD for a 115-year (1901-2015) period published in January 2018 revealed a significantly declining trend in Arunachal Pradesh and NMMT subdivisions. However, the analysis revealed that the frequency of extreme rainfall events is increasing. 

This overall drying trend, interspersed with extreme rainfall events that cause floods, is a sure sign of global warming and the resulting climate change affecting India’s northeastern region. This trend has been evident in the region for several decades, particularly in Assam and Nagaland.