El Niño system may affect upcoming winter season in Maha

PUNE: As El Niño is still in its active phase, it is likely to have an impact on the upcoming winter season, experts have noted, adding that El Niño can contribute to an increase in temperature. As a result, there may be a warm winter this year, including in Maharashtra. However, how significant the temperature rise will be is yet to be ascertained, the researchers said.

Anupam Kashyapi, head of the weather forecasting division, IMD Pune, said, “The El Niño is likely to affect the upcoming winter season. It mainly contributes to a temperature rise. Therefore, the country as well as the state will experience an increase in temperature however it is still not clear how much it will affect the winter season. Moreover, an increase in temperature may also affect the Rabi crops in many areas as crops such as jowar, wheat, chickpea or gram require cooler weather.”

Vineet Kumar, a former researcher from the Indian Institute of Tropical Meteorology (IITM), said that overall due to the impact of El Niño, Maharashtra may see temperatures one or two degrees Celsius above normal temperatures in the winter season between November and January.

El Niño is a climate pattern which describes the unusual warming of surface waters in the eastern tropical Pacific Ocean. This year, India is experiencing an active phase of this weather system. The El Niño started in July and is expected to continue till the early phase of next year, namely February to March 2024. The El Niño had a significant impact on the southwest monsoon, especially during August when the country experienced a month-long monsoon break. Although Positive Indian Ocean Dipole (IOD) conditions compensated for the El Niño effect, overall rainfall received was on the negative side of normal. Furthermore, the state this year experienced early withdrawal of the monsoon compared to the delayed withdrawal pattern of the last five years. This resulted in comparatively less rainy days during the monsoon phase. Immediately after the withdrawal of the monsoon, the state saw a significant rise in maximum temperature in some areas. This rise was a clear indication of the El Niño impact on weather in Maharashtra, according to an IMD official.

Regarding the impact of active El Niño conditions on cyclone formation in the Bay of Bengal, Kumar said, “On an average, two to three cyclones per year form in the Bay of Bengal during the post-monsoon season between October and December. However, in an El Niño year, the frequency of cyclones is close to 1.6 (only one or two cyclones). Also, the intensity of cyclones in the post-monsoon season in the Bay of Bengal is about 25% less than normal. As per JTWC data, during the last four decades in El Niño years, only three ‘category 1 or higher intensity’ cyclones (windspeeds of at least 120 kmph) have formed in the post-monsoon season in the Bay of Bengal. No category 4 or higher intensity cyclones (windspeeds of at least 220 kmph) have formed when there is El Niño.”

Kumar said that IOD too has an impact on cyclone activity in the Bay of Bengal, with negative IOD enhancing cyclone formation in the bay and positive IOD suppressing it. “This year, El Niño and positive IOD have suppressed cyclone formation and intensity in the Bay of Bengal. As a result, the cyclone activity in the Bay of Bengal this post-monsoon season is expected to be significantly below normal,” Kumar said. He said that the impact of El Niño on Arabian Sea cyclones is not clear and more research is required in that area.