Temperatures during the day are expected to be normal to below normal over most parts of the country except parts of southern peninsular India, northeast, and northwest India, forecast by the India Meteorological Department (IMD) stated.
Night temperatures, however, are expected to be above normal across many parts of the country.
Parts of northwest India, along with some parts of central India and adjoining areas of peninsular India and southern parts of northeast, are likely to experience normal to below-normal minimum temperatures.
A milder May is expected mainly because of a higher likelihood of thunderstorm activity over several parts of the country and an increased frequency of western disturbances.
India Meteorological Department (IMD) officials said they have been observing an increase in WDs since March; moisture incursion from Arabian Sea has strengthened WDs.
There are likely to be above-normal heatwave days over some parts of the foothills of the Himalayas, east coast states, Gujarat and Maharashtra in May.
The rainfall during May, averaged over the country as a whole, is likely to be above normal (>110% of LPA). The long period average of rainfall over the country as a whole during May based on data of 1971-2020 is about 61.4mm. The normal to above-normal rainfall is likely over most parts of the country except some parts of east and northeast India and east central India where below normal rainfall is likely.
Also Read: Rain, gusty winds to bring respite from heatwave in region: IMD
Currently, ENSO-neutral conditions are evolving toward El Niño conditions over the equatorial Pacific, IMD said. There is a 60% probability of El Nino conditions establishing during May, June and July, IMD projected.
El Nino conditions are expected to prevail through the monsoon season till the end of the year.
At present, neutral Indian Ocean Dipole (IOD) conditions are prevailing over the Indian Ocean. The latest climate models indicate that Positive IOD conditions are likely to develop towards the end of the monsoon season.
El Niño and La Niña are opposite phases of the El Niño–Southern Oscillation (ENSO), a natural climate cycle driven by changes in ocean surface temperatures in the central and eastern equatorial Pacific.
El Niño, the warmer phase, typically occurs every two to seven years, lasts around nine to 12 months, and is associated with drought over Australia, Indonesia and parts of southern Asia, and increased rainfall in parts of southern South America, the southern US, the Horn of Africa and central Asia. In India, the El Nino saps the monsoon season of rains. A positive IOD helps enhance the monsoon.
“We are expecting more WDs and more thunderstorm activity in May. This is not necessarily linked to the evolving El Nino,” said M Mohapatra, director general, IMD.
During May, above normal heatwave days (3-4 more days) are likely over some parts of the foothills of the Himalayas especially southern Himachal Pradesh, Uttarakhand, northeast Bihar, east coast states, Gujarat and Maharashtra.
IMD’s extended range forecast shows, there is likely to be above-normal rainfall activity especially over east and northeast India till May 7. The day temperatures are expected to be high over NW India during the second week and fourth week of May.
During April, rainfall over the country was 11% below normal; 7.4% excess over NW India; 10.8% below normal over east and northeast India; 17.2% excess over central India and 51.1% deficiency over South Peninsula.
IMD’s projections indicate that southwesterly winds are expected to pick up over Bay of Bengal in the week of May 14 to 20. Monsoon normally arrives over Andaman Sea around May 20.
