Flood responses to increases in rainfall extremes vary depending on event severity

There is clear evidence that precipitation extremes will increase in a warming climate. However, the hydrologic response to this increase in heavy precipitation is more uncertain - and there is little historical evidence for systematic increases in flood magnitude despite observed increases in precipitation extremes. These dual realities yield a paradox with considerable practical relevance: will the divergence between extreme precipitation increases and flood severity persist, or are land-surface processes at work?  Here, we investigate how flood magnitudes in hydrological Bavaria change in response to warming using a single model initial condition large climate ensemble coupled to a hydrological model (hydro-SMILE). We find that there exists a severity threshold above which precipitation increases clearly yield increased flood magnitudes, and below which flood magnitude is modulated by land surface processes. Our findings highlight the importance of large ensembles and help reconcile climatological and hydrological perspectives on changing flood risk in a warming climate.