IMD forecasts severe heatwave in North India
The India Meteorological Department (IMD) has issued a severe heatwave warning for northern India, including Delhi, Punjab, and Haryana, effective from Saturday to Monday (May 18 to 20). The forecast also anticipates similar conditions in other parts of northern India and Bihar over the next five days. IMD Director General M Mohapatra stated that there is "no immediate chance of rain" and conditions will remain very hot for the next seven days.
Rising temperatures expected in Northwest India and Gujarat
Temperatures in northwest India and Gujarat are also projected to increase by 2-3 degrees over the next five days due to the diminishing influence of western disturbances. Mohapatra explained that this is due to "subsidence of hot air, which is heating the surface due to an anticyclone over northwest India." He also warned that soon there will be "advection of hot air toward UP and Bihar." Advection is the transfer of heat through the horizontal movement of air.
Southern India to experience contrasting weather
In contrast to the north, southern India's weather is expected to be significantly different due to a cyclonic circulation over Kanyakumari in Tamil Nadu. This circulation is predicted to bring 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. Similar conditions are likely over coastal Andhra Pradesh, Yanam, Telangana, and Rayalaseema during the same period.
Heatwave criteria and alert levels explained
The IMD declares a heatwave when the maximum temperature exceeds 40°C over plains, 37°C in coastal areas, and 30°C in hilly regions with a deviation from normal between 4.5°C and 6.4°C above average maximum. A severe heatwave is declared when the deviation exceeds 6.4°C above normal. Heatwaves usually occur from March to June and, in some cases, even July. The peak month of the heatwave over India is May, according to the IMD.
