Tropical Cyclone ‘Biparjoy’: a blessing in disguise for the Disastrous heat wave event of June 2023 over India

Abstract

The June 2023 heat wave over eastern and northern India was driven by a complex interplay between synoptic-scale meteorological patterns and tropical cyclone activity. A persistent mid-to-upper tropospheric ridge over the region during 14–18 June led to strong subsidence, clear skies, and stable atmospheric conditions, fostering intense surface heating. Concurrently, Extremely Severe Cyclonic Storm (ESCS) Biparjoy developed over the northeast Arabian Sea and made landfall over Gujarat on 15 June. Prior to landfall of Biparjoy, strong northwesterly winds at lower levels, advected hot, dry air from arid regions into the eastern Indo-Gangetic Plains, intensifying heat wave conditions. The event was marked by both extreme daytime temperatures and elevated nighttime minima, reducing nocturnal cooling and heightening heat stress. Following landfall, the remnant circulation of Biparjoy disrupted the prevailing northwesterlies and weakened the ridge pattern, resulting in reduced hot air advection and a 3–6°C drop in maximum temperatures across affected regions.            This evolution led to the gradual abatement of heat wave conditions over northwest, central, and eastern India. The case highlights a notable contrast in the role of tropical cyclones by origin: while Bay of Bengal systems may tend to intensify heat waves, Arabian Sea cyclones such as Biparjoy may moderate them post-landfall. These findings emphasize the importance of cyclone origin, trajectory, and interaction with continental systems in modulating heat extremes, and advocate for integrating tropical cyclone forecasting into heat wave preparedness strategies.