March-May may be warmer than normal: IMD
Winter is officially over and the coming summer promises to be warmer than normal in most subdivisions of northwest, west and central India and some parts of peninsular India.
And according to the weather office, at this point in time, chances of El Nino, a weather phenomenon associated with deficient monsoons in India, are low.
A forecast for March, April, May by the India Meteorological Department (IMD) released on Friday said above- normal heat wave conditions are likely in the so-called core heat wave (HW) zone. This covers Punjab, Himachal Pradesh, Uttarakhand, Delhi, Haryana, Rajasthan, Uttar Pradesh, Gujarat, Madhya Pradesh, Chhattisgarh, Bihar, Jharkhand, West Bengal, Orissa and Telangana, subdivisions of Marathawada, Madhya Maharashtra and coastal Andhra Pradesh.
The heat wave zone refers to areas prone to heat waves. According to IMD, heat wave is recorded when departure of maximum temperature from normal is + 4 degree C to + 5 degree C or more for the regions where the normal maximum temperature is more than 40 degree C and departure of maximum temperature from normal is + 5 degree C to + 6 degree C for regions where the normal maximum temperature is 40 degree C or less (Heat Wave is declared only when the maximum temperature of a station reaches at least 40 degree C for plains and at least 30 degree C for hilly regions). Heat wave is also declared when actual maximum temperature remains 45 degree C or more irrespective of normal maximum temperature.
And even in the absence of a heat wave, these areas will be hotter, the IMD forecast said. There is about a 43% probability of maximum temperatures in the core heat wave zone being above normal.
The forecast indicates average temperatures are likely to be higher than normal by at least 0.5 degree C in northwest, west and central India and some subdivisions in south India. Near normal temperatures are likely in the remaining subdivisions.
The mean temperatures for the three months are likely to be higher than normal by at least 1 degree C in Himachal Pradesh, Uttarakhand and West Rajasthan.
The maximum temperatures are also expected to be at least 1 degree C higher in Himachal Pradesh, Uttarakhand, West Rajasthan and Arunachal Pradesh.
The forecast also said that warm El Nino Southern Oscillation (ENSO)-neutral conditions are prevailing over equatorial Pacific Ocean and that the latest forecast indicates cooling of sea surfaces temperatures in summer leading to ENSO neutral conditions. El Nino is a weather phenomenon characterised by warm ocean temperatures in the equatorial Pacific Ocean. El Nino years are characterised by a weak monsoon and more episodes of heat waves in India.
“The El Nino conditions may be neutral but the global warming trend is associated with above normal temperatures. The forecast will be updated in March”, he added.
“Higher than normal temperatures could be because of many reasons. It could be due to intense heating but we have to remember that this is a general forecast for all three months. There will be day-to-day variation. It’s a climate forecast. The climate forecasting model we are using is indicating above average temperatures but we will know the reasons later. The forecast is mainly for planning purposes,” said K Sathi Devi, head, National Weather Forecasting Centre.
IMD, in its seasonal outlook for April to June last year, predicted maximum temperatures that were higher than normal by 0.5 to 1 degree C in most parts of central and some parts of northwest India. Above normal heat wave conditions were also forecast over the core heat wave zone. Weak El Niño conditions were prevailing over the equatorial Pacific Ocean last summer.
The 2019 annual mean land surface air temperature for the country was 0.36 degree C above the 1981-2010 period average, making 2019 the seventh warmest year on record since 1901. The five warmest years on record in order are : 2016 (+0.71 degree C), 2009 (+0.541 degree C), 2017 (+0.539 degree C), 2010 (+0.54 degree C) and 2015 (+0.42 degree C) and 11 out of 15 warmest years have been during the past 15 years.
“Average temperatures in the pre-monsoon season could be higher than normal due to low pre-monsoon rains in northwest India. Sea surface temperatures are also slightly above normal, which will also contribute to higher summer temperatures,” said Mahesh Palawat, Vice President, Climate and Meteorology, at private forecaster Skymet Weather.