Abstract Predicting and understanding drivers of post‐fire floods is necessary for natural resources, infrastructure, and emergency managers in a regime of larger, more severe wildfires that increasingly intersect with human populations and infrastructure. Post‐fire flood prediction remains a challenge due to data limitations combined with the influence of spatial and temporal precipitation variability. We propose a large‐sample Paired Storms Framework that applies the concepts of the established paired watersheds approach but exchanges time for space by identifying and characterizing post‐fire peak flow (PFPF)‐producing storms, identifying similar (i.e., paired) storms in a watershed's undisturbed record, and quantifying post‐fire changes in peak flow response to paired storms. We characterize storms associated with PFPFs based on 26 identified PFPFs across seven western U.S. watersheds. PFPF‐producing storms generally occurred in wet years, with high 60‐min maximum intensities and storm depths, were centered in the headwaters, and fully overlapped the watershed and burned area. 75% of analyzed PFPF magnitudes were at least two times greater than their paired storm peak flow magnitudes, with the largest observed change being 39 times greater. This framework and study findings can support post‐fire flood forecasting, mitigation, and critical infrastructure design in wildfire‐prone watersheds in the western U.S.
Canham et al. (Sun,) studied this question.