In the present study, we analyse large‐scale connections to deadly heatwaves in India in spring. Deadly Indian heatwaves occur in the spring months of April and May, and are increasing in recent years. These events are associated with the amplification of planetary Rossby waves. This amplification is called quasi‐resonant amplification (QRA). An increase of amplitude or resonance occurs when stationary and moving waves coincide in their size. Previous studies stressed QRA's role in summer because persistent extreme weather events such as the 2003 European heatwave, the 2010 Pakistan flood, Russian heatwave, the 2011 Texas and Oklahoma heat waves, and drought occurred in summer. QRA seems to be related to the amplification of Arctic warming in winter and summer, but observations show that Arctic warming occurs in spring also. The novel aspect of our study is that we found strong evidence for QRA in the boreal spring, the season of Indian heatwaves. Amplified Arctic warming or Arctic amplification thought to be responsible for QRA occurs in spring also. Our results confirm that maximum surface temperatures in spring over India show predictability with high statistical significance, about 4 days ahead. Maximum surface temperatures can be used to predict heatwaves, as shown earlier by some authors.

In this paper, the authors suggest a dynamical mechanism involved in the revival of the summer monsoon after breaks. In this context, the authors carry out a diagnostic analysis using the datasets from National Centers for Environmental Prediction Reanalysis 2 for the period 1979–2007 to identify a robust mechanism that typifies breaks and subsequent revival of monsoon. The authors find during the peak of significant breaks an anomalous southward shift of the subtropical westerly jet stream, which is invariably accompanied by an anomalous northward shift of a stronger-than-normal easterly jet. These major changes during a break facilitate an instability mechanism, which apparently leads to formation of a synoptic disturbance. Formation of such a disturbance is critical to the subsequent revival of the summer monsoon in 61% of the observed break-to-active revivals.Computations of energetics and correlation analysis carried out suggest an increase in the eddy kinetic energy at the expense of the mean kinetic energy during the breaks, in agreement with the formation of the synoptic disturbance. This demonstrates that barotropic instability in the presence of a monsoon basic flow is the primary physical mechanism that controls the revival of the summer monsoon subsequent to the break events.