Western Disturbance Breaks and Extreme Spring Heat Over Northern India Linked to Quasi‐Stationary Rossby Waves

Abstract Spring heat extremes over northern India in March coincide with critical wheat growth and pose disproportionate risks to yield and food security. March surface temperatures are modulated by Western Disturbances (WDs), midlatitude cyclonic systems embedded in the subtropical jet that typically bring rain and cooling. Using isobaric temperature tendency diagnostics, wave‐activity flux, and surface energy‐budget analysis, we show that the most extreme surface heat events follow the onset of a WD break and occur within a persistent circulation regime characterized by a quasi‐stationary Rossby wave emanating from a European high visible days in advance. This wave pattern further blocks WDs and produces an extended WD break period during which enhanced subsidence warms the atmospheric column. Concurrently, increased shortwave radiation and reduced longwave cooling at the surface amplify near‐surface temperatures. Together, these results link remote stationary‐wave forcing to local land–atmosphere amplification, explaining why modest surface warming events escalate into March heat extremes.