Besides La Niña, North Indian winters are also dominated by western disturbances. (Getty)
The Met Department predicts warm but rainy October. However, the magnitude of this winter’s cold wave will largely depend on the strength of La Niña, which is still far away
Uncertainty surrounds the arrival of La Niña – a global phenomenon that could have a major impact on temperatures in India this winter. According to the latest forecast, there is at least a 60-70% chance that La Niña could arrive within the next two months, which also marks the beginning of the winter season in India.
“Typically, temperatures in Northwest India are below normal during La Niña years. But in this case, the forecast of its change is not predicted very accurately around the world. The current situation suggests that it can be weak. If so, Northwest India may experience cold waves this winter but at the moment, it is difficult to predict how severe they will be,” said Dr M Mohapatra, chief of the India Meteorological Department (IMD).
La Niña is a natural scientific phenomenon that occurs when temperatures over the equatorial Pacific Ocean begin to cool. This change affects the climate of all countries as it changes the movement of air around the world. In India, it strengthens the southwest monsoon, and makes the winter cold and harsh, especially in the northwest region. But if La Niña is very strong, then its effect is evident in parts of the southern peninsula.
For the longest time, global forecasters have predicted that La Niña will set itself between July and August Soon after El Nino Wanes. Instead, neutral ENSO conditions prevailed until August and equatorial ocean temperatures remained unusually warm – delaying the arrival of La Niña.
But the situation is now starting to change – at least slowly.
Most of the world’s forecasters, including the US-based National Oceanic and Atmospheric Administration (NOAA), are confident of a 70 percent chance of La Niña during October-November. Unlike previous predictions, it will be very weak, and temporary. It is expected to increase only in late January-February, and continue in March next year.
“Usually, La Niña first appears in August-September and reaches its peak in December, but surprisingly it did not happen. Now if it happens to be visible, then there is a good chance that it may not be strong, which would make the winter difficult. This is because once the temperature of the equatorial ocean cools, the prevailing winds also need time to react and influence the climate. Until there is a surprise,” said Professor Raghu Murtugudde of IIT Bombay.
Apart from La Niña, winters in North India are also dominated by western disturbances. These storms moving over the Mediterranean Sea towards the West of the Himalayas can bring rain and snow and lower temperatures considerably in December-January. However, it is too early to predict their performance this winter.
Meanwhile, the IMD has already predicted above normal day and night temperatures in most parts of India this October, except for some parts of Central India, and the south and the peninsula including eastern Rajasthan, Madhya Pradesh, Chhattisgarh, Telangana, and Maharashtra where possible. normal to below-normal. Monthly rainfall is also predicted to be above normal – averaging 115 percent above the long-term average (LPA).
The year 2024 is already on track to be the hottest year globally after a string of monthly record temperatures. The July-August period was the hottest on record, on par with 2023, and marked the beginning of extreme weather conditions around the world. However, a clearer picture will emerge from the Met’s winter outlook to be released in November, followed by extended range forecasts released every two weeks.