La Nina conditions may bring harsh winter to North India
The India Meteorological Department (IMD) has forecast a potentially severe winter for north and northwest India, including Delhi-NCR. This prediction is based on the expected formation of La Nina conditions by October-November. IMD chief Mrutyunjay Mohapatra stated that there is a 71% chance of these conditions developing during this period.
La Nina's impact on India's climate and agriculture
La Nina is a climate phenomenon that's all about the periodic cooling of ocean surface temperatures in the central and east-central equatorial Pacific. While it didn't show up during the southwest monsoon months like global models predicted, it's usually linked to good monsoon rainfall in India. Mohapatra explained that during La Nina years, "temperatures in the northern part of the country...are below normal (colder than normal)... So, you can have cold wave conditions during winter months."
La Nina's severity and impact on winter still uncertain
The intensity of the upcoming winter is still up in the air, as the La Nina condition is still on the weaker side. The Met department will keep an eye on its strengthening in January or February to give a more accurate forecast in November. Even though La Nina wasn't around during this year's monsoon, India still saw above-normal rainfall, due to other factors like six depressions and 14 low-pressure systems in the Bay of Bengal.
Above-normal rainfall benefits agriculture and hydro-power generation
This season's above-average rainfall has significantly impacted agriculture, increasing the sown area for kharif crops and replenishing reservoirs critical for rabi crop irrigation. Additionally, the surplus rain has provided a substantial boost to hydro-power generation. Regionally, arid west Rajasthan received 71% more rainfall than normal, while west Gujarat experienced an even higher surge with a 75% increase over its seasonal average.
Regional variation in rainfall observed across India
Mohapatra pointed out that the "large excess" rainfall in west Rajasthan and west Gujarat was due to the formation of more "low pressure systems" and "depressions." He also mentioned that the monsoon trough stayed south of its usual position, leading to "large excess" rains in these areas. Out of 36 meteorological subdivisions in India, two got large excess rainfall, 10 got excess, 21 got normal rainfall, while three (Arunachal Pradesh, Punjab, J&K, and Ladakh) received deficient seasonal rainfall.
