On the storm direction and peak floods in the continental United States, 1950–2024

Storm direction has significant impacts on land surfaces, such as flood responses and soil erosion. With projected increases (e.g., frequency and magnitude) in extreme precipitation events across many regions of the world, it is worthwhile to explore possible changes in storm characteristics, especially as more data have become available during the satellite era over the past three decades. In this study, we focus on understanding and characterizing storm directions over the continental United States (CONUS). Specifically, a new storm direction model is developed and applied to model-based reanalysis (ERA5L, 9 km resolution) and surface measurement-based reanalysis (AORC, 4 km resolution). This study shows strong variability in storm directions over the Great Plains and spatial patterns of storm preferential direction related to topography and climate regimes across CONUS. This study also reveals differences in storm travel distance, storm duration, and estimated probable maximum precipitation at event scales, conditional on whether the storm comes from a preferential or non-preferential direction. For example, the median storm travel distance is increased by 35 km when storms come from the preferential direction. Flood peaks are higher by a median of 50-100% when stream directions align with storm directions. The AORC produces good estimations of probable maximum precipitation derived from this new storm direction model, particularly along the southern coasts.