Severe heat wave returns in North, Central India

North and Central India are set for a fierce heat spell from Monday, June 8, with temperatures climbing to 46 degrees Celsius.

This is predicted because the mercury is set to climb from Monday, June 8.

Independent weather forecaster Navdeep Dahiya has flagged a sharp rise in daytime temperatures across Punjab, Haryana, Rajasthan, Delhi-NCR and Uttar Pradesh, with maximums touching 42 to 46 degrees Celsius.

The peak is likely around June 10 and 11, before some relief arrives by Friday.

The main culprit is a steady stream of hot, dry winds blowing in from the northwest. Scientists call this advection, which simply means heat being carried from one place to another by the wind.

Here, the winds sweep across the Thar Desert and the dry plains of Rajasthan and Pakistan, soaking up heat as they travel.

These are the infamous loo winds, the dusty, parching gusts that strip moisture from the air and from your skin. Because they keep flowing, any cool air that forms locally is quickly shoved aside and replaced with more hot air.

There is a second player at work high above us. A ridge of high pressure, also called an anticyclone, often parks itself over the region. Picture an invisible lid that presses warm air downwards.

As this air sinks, it gets squeezed and warms up further, a process known as subsidence.

The lid also clears away clouds, so the strong June Sun beats down with little to block it. The outcome is sometimes called a heat dome, where warmth is trapped near the ground.

Dry soil makes it worse. With little moisture left to evaporate, almost all the Sun’s energy goes into heating the air rather than turning water into vapour, which is why parched land bakes fastest.

India Today