The Roles of Subtropical Westerlies on Heat Waves Extremes Over Northwestern South Asia in Early Spring 2022

ABSTRACT The unprecedented early spring (March–April) 2022 heat waves over Northwestern South Asia (NWSA) were marked by record‐breaking temperatures and prolonged heat wave extremes. The area‐averaged maximum temperature anomalies over NWSA reached 4.2°C above the 1976–2021 climatological mean, and the area‐averaged heat wave frequency (HWF) peaked at 26 days. This study examines the northward shift of the subtropical westerly jet and atmospheric subsidence feedback related to these extreme events. Zonal wind at 200 hPa shows a northward displacement of the subtropical westerly jet axis from its climatological position (around 28°N) to approximately 1110 km northward (maximum shift) over the latitudes of NWSA in 2022. Statistically significant strong positive (negative) anomalies between 35°N and 60°N (10°N and 35°N) at upper levels (200–300 hPa) indicate enhanced (reduced) westerly winds in the subtropical jet stream region and stagnant atmospheric conditions over NWSA. Persistent geopotential height anomalies at 200 (500) hPa established a vertically coherent high‐pressure ridge that drove subsidence over NWSA. Suppressed cloud cover (10%–20% decline) and increased surface net shortwave radiation (20–30 W m −2 ) enhance the near‐surface temperatures. Thus, the northward displacement of the jet, high‐pressure dominance, and radiative feedback collectively prolonged the heat wave conditions over NWSA. Improved monitoring of jet stream dynamics and geopotential height patterns can enhance heat wave predictability over NWSA in a warming climate.