Harsher winter ahead, La Nina could affect monsoon also

Winter may be relatively harsher and longer in north India this year as La Niña, a global weather pattern that has a cooling effect on global weather conditions, has matured and nearly peaked.The World Meteorological Organization (WMO) said that various meteorological parameters indicate that La Niña, which began in September, is approaching its peak and may return to neutral conditions only late next summer.

Scientists said this could mean a long, harsh winter in north India and could have an impact on the coming monsoon depending on the status of La Niña in May, June and July. La Niña is only one of a range of climatic drivers which affect weather globally. Other drivers include the Indian Ocean Dipole and Madden-Julian Oscillation. Forecasting the expected impacts of La Niña can therefore be complex, WMO, said adding that it has started mobilising preparations for impacts of La Niña. The National Oceanic and Atmospheric Administration has estimated that there is 95% probability of La Niña continuing through March 2021.

"Below normal temperatures are expected over northwest India through the winter. Generally, La Niña helps the Indian monsoon which means above normal rains are expected but its too early to give a specific forecast for monsoon. We know that cold westerlies tend to enter inland during La Niña years which is also why winter is more pronounced,” said DS Pai, senior scientist at India Meteorological Department, Pune. 

The peak of winter chill is likely to be felt in the first week of January as a couple of western disturbances are likely to bring widespread snowfall to the western Himalayan region. If La Niña conditions immediately don’t switch over to El Niño when sea surface temperatures are very warm then monsoon in the coming year is also likely to be above normal,” explained Mahesh Palawat, vice-president, climate change and meteorology, Skymet Weather.