IMD forecasts more days of heat in eastern India in May.
According to the IMD's monthly outlook statement, "Normal to above-normal rainfall is expected over northwest India, parts of west-central India, and the northern part of peninsular India." Over the majority of northeast India, east-central India, and the southern peninsula, below-normal rainfall is likely.
Over Bihar, Jharkhand, Odisha, Gangetic West Bengal, East Uttar Pradesh, coastal Andhra Pradesh, Chhattisgarh, Madhya Pradesh, Telangana, and coastal Gujarat, there will be more heatwave days than usual. While mercury levels in these regions of India do not rise as high as they do in north and northwest India during heatwaves, the combination of higher humidity levels and the heat poses a relatively higher health risk.
According to the India Meteorological Department (IMD) on April 28, May, typically the hottest month in most of India, is likely to be particularly hot in large portions of eastern India, but Delhi, Punjab, Haryana, Rajasthan, and Gujarat — while still hot — are likely to see increased rain and limited heatwaves.
According to the statement, rainfall in May is probably going to be "average" or within a 10% range of what's typical for the month. Temperatures that are consistently exceeding 45 degrees Celsius, or 4-5 degrees higher than what is typical for a location, are what are referred to as heatwaves.
Because of rain that will keep temperatures [relatively] low, our current forecasts indicate that there might not be many days of heatwaves in the northwest, according to IMD Director-General Mrutunjay Mohapatra.
The IMD forecast a 4% shortage for the upcoming monsoon season in April. Although it is still considered "normal," the rainfall was at the low end of what the agency considers to be "normal" at 96% of the Long Period Average (LPA). El Nino, a cyclical occurrence of warming in the Central Pacific associated to less rainfall in the west, northwest, and western regions of Central India, is thought to be the main reason causing havoc this year.
Since 2019, India has been affected by the opposite "La Nina," or a cooling in those areas, resulting in heavy monsoon rain. According to the most recent "El Nino" forecast, warming in the equatorial Pacific has started and is expected to increase by 1 degree Celsius in the months of July, August, and September. The 'El Nino' would be moderate, according to Mr. Mahapatra.
Over 1°C is considered a "moderate El Nino," while a rise of more than 1.5°C is considered a "severe El Nino". In the Central, Equatorial Pacific Ocean, there have been 15 "El Nino" years between 1951 and 2022, with nine of those years experiencing "below-normal" rainfall. El Nino is defined as a temperature increase of more than half a degree Celsius. The monsoon rain decreased by 14% in 2015, the most recent "severe El Nino" year (>1.5°C rise).