Geophysical Drivers of the Northwest India Heatwave: Analyzing the 'Heat Dome' Effect

The India Meteorological Department (IMD) has issued a 'Red Alert' for Delhi, Punjab, and Haryana as a relentless heatwave pushes temperatures beyond 47°C. This extreme weather event is not merely a seasonal spike but is driven by specific geophysical factors that warrant a deep dive for civil services aspirants. Two primary drivers have been identified: the 'Heat Dome' effect and the absence of Western Disturbances. A Heat Dome occurs when a persistent region of high pressure traps heat over a specific area, much like a lid on a pot. This high-pressure system compresses the air below it, heating it further through adiabatic compression and preventing clouds from forming, which would otherwise provide relief. Simultaneously, the region has seen a lack of Western Disturbances—extra-tropical storms originating in the Mediterranean region. Usually, these disturbances bring moisture and cooling thundershowers to Northwest India during spring and early summer. Their absence has left the region vulnerable to dry, hot winds from the desert regions of Rajasthan and Pakistan.