Influence of Weather Fronts on Design Storm Profiles: Applied Event Partitioning and Comparative Analysis

Abstract Current practices in hydrologic design are based on the exceedance probability of rainfall intensities, without considering the meteorological conditions that generate them. Atmospheric drivers, such as weather fronts, control the spatiotemporal characteristics of storm events, with implications for urban stormwater infrastructure design and analysis. In this study, over 700 historic events were objectively partitioned into their respective frontal storm signatures for a hydrologically uniform climate region of more than 14,000 km 2 , represented by 10 distinct weather stations. Our analysis showed that fronts have distinctive temporal persistence characteristics. Notably, cold front events displayed patterns of larger variability than warm front events across all stations. Furthermore, synthetic storm profiles were developed through a dimensionality reduction and intuitive averaging framework initialized by bootstrap resampling, which yielded distinct storm shapes under different air mass regimes. We also found that the temporal development of frontal storms significantly departs from the widely‐used center‐peaking NRCS storm distribution. Besides, the seasonality of storms was found to play a confounding role, where summer storms, no matter what front type, display peak rainfall intensities in the first half of their respective time series, suggesting prevalent convective storm activity. Based on this analysis, we conclude that for design storms where only the maximum intensity or static depth is of interest, frontal partitioning plays a limited role. In contrast, where temporal loading impacts performance, such as for nature‐based solutions, the secondary effects of frontal storm event shape are consequential.