New Delhi: A severe heatwave will likely envelope Delhi, Punjab and Haryana between May 18 and 20, the India Meteorological Department (IMD) forecast on Thursday, adding that similar conditions will grip other parts of northern India and Bihar over the next five days as the summer heat cranks up across most parts of the country.
Temperatures in northwest India and Gujarat will rise by two to three degrees over the next five days, warned the agency, attributing the spiralling heat to the dwindling influence of western disturbances.
“There is no immediate chance of rain. There is also subsidence of hot air, which is heating the surface due to an anticyclone over northwest India. Soon, there will be advection of hot air towards UP and Bihar also. Conditions will remain very hot for the next seven days,” said M Mohapatra, director general, IMD.
Advection is the lateral movement of hot air due to winds. Private weather forecasters concurred with IMD’s prediction.
“There is an anticyclone over West Rajasthan and Pakistan, causing the incursion of hot air from Balochistan and Thar desert. Heatwaves have started in parts of Rajasthan and some parts of Delhi also met the heatwave criteria on Wednesday.
The area impacted by heatwaves will increase,” said Mahesh Palawat, vice-president, climate and meteorology at Skymet Weather.
The Met department declares a heatwave when the maximum temperature is over 40°C over the plains; over 37°C over coastal areas and over 30°C over hilly regions, even as the deviation from normal is between 4.5°C and 6.4°C above the average maximum.
If these conditions persist for two consecutive days, a heatwave is declared on the second day. A severe heatwave is declared when the deviation is more than 6.4°C above normal.
IMD has also declared an “orange alert” for Punjab, Haryana and west Rajasthan on May 18, 19 and 20, which implies that local authorities need to be prepared to prevent heatwave-related exigencies.
The warning adds that there is an increased likelihood of heat-related illnesses among people who are either exposed to the sun for a prolonged period or doing heavy work and high health concerns for vulnerable people.
However, southern India’s weather has been in marked contrast, owing to a cyclonic circulation over Kanyakumari in Tamil Nadu and the adjoining southern fringes of the state that has brought rain to vast swathes of peninsular India.
This circulation has brought with it the possibility of widespread light to moderate rainfall, accompanied by thunderstorms, lightning and gusty winds) over Tamil Nadu, Puducherry, Karaikal, Kerala, Mahe, Lakshadweep and south Karnataka over the next seven days.
Similarly, light to moderate rainfall accompanied with thunderstorms, lightning and gusty winds (30-40 kmph) are likely over coastal Andhra Pradesh, Yanam, Telangana and Rayalaseema over this same period.
IMD has also warned of flooding across Tamil Nadu.
