Winter may be relatively harsher and longer in northern India this year as La Niña, a global climate model that has a cooling effect on global weather conditions, has matured and almost peaked.
The World Meteorological Organization (WMO) said various meteorological parameters indicate that La Niña, which started in September, is nearing its peak and could only return to neutral conditions at the end of next summer.
Scientists have said this could mean a long, harsh winter in northern India and could impact the oncoming monsoon depending on the state of La Niña in May, June and July.
La Niña is just one of a number of climatic factors that affect weather globally. Other drivers include the Indian Ocean Dipole and the Madden-Julian Oscillation. Predicting the expected impacts of La Niña can therefore be complex, the WMO said, adding that it has begun to mobilize preparations for the La Niña impacts. The National Oceanic and Atmospheric Administration has estimated that there is a 95% chance that La Niña will continue through March 2021.
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WMO said on Wednesday that Southeast Asia is expected to see a typical weather response in La Niña over the next three months, with wetter-than-average conditions affecting most parts, particularly the Philippines, with increased risk of floods and landslides.
“We have already mentioned that lower than normal temperatures are expected in Northwest India during the winter. In general, La Niña helps the Indian monsoon, which means that higher than normal rains are expected, but it is too early to provide a specific forecast for monsoons. We know that cold westerly winds tend to come inland during the La Niña years, which is why winter is more pronounced, ”said DS Pai, senior scientist at the Indian Meteorological Department of Pune.
“It looks like winter conditions will be severe until February and this could be a prolonged winter. The La Niña years are associated with longer winters. The peak of winter cold is likely to be felt in the first week of January, as a couple of western disturbances could bring heavy snowfall to the western Himalayan region. If conditions in La Niña do not immediately switch to El Niño when sea surface temperatures are very warm, next year’s monsoons are likely to be above normal as well, “explained Mahesh Palawat, Vice President, Climate Change and meteorology, Skymet Weather.
“Both October and November were colder than normal in Northwest India, which may be related to La Niña. Another period of very low temperatures could occur by the end of the month and the beginning of January, “said RK Jenamani, senior scientist, National Weather Forecasting Center.
El Niño and the Southern Oscillation (ENSO) is a periodic fluctuation of the sea surface temperature and atmospheric pressure of the overlying atmosphere across the equatorial Pacific Ocean according to the National Oceanic and Atmospheric Administration (NOAA).
ENSO has a great influence on weather and climate patterns such as heavy rains, floods and droughts. El Niño has a warming influence on global temperatures, while La Niña has the opposite effect. In India, for example, El Niño is associated with drought or weak monsoon, while La Niña is associated with strong monsoons and above-average rainfall and colder winters.
IMD, in its seasonal forecast for winter, said nights and early mornings would likely be cold, with sub-normal minimum temperatures in most parts of the north, northwest, central and parts of the country. Eastern India, while daytime temperatures are expected to be above normal in the same regions. Daytime temperature variation (difference between day and night temperatures) is likely to be high in most subdivisions of northern, northwestern, central India and some subdivisions of eastern India.
WMO also said in a statement Thursday that this decade (2011-2020) is the hottest and this year remains on track to be one of the three hottest on record, despite a refreshing event in La Niña, which now it is mature and has an impact on weather patterns in many parts of the world.
“Record hot years usually coincide with a strong El Niño event, such as in 2016. We are now experiencing a La Niña, which has a cooling effect on global temperatures, but has not been enough to hold back the heat. Despite the current conditions. of La Niña, this year has already shown a near-record heat comparable to the previous record of 2016, “said WMO General Secretary Petteri Taalas.