Leveraging the Atmospheric River Framework to Categorize Top‐Decile Precipitation Regimes in Colorado

Abstract This study investigated four top‐decile precipitation regimes in Colorado (CO) using a k‐means clustering approach. Two cool‐season regimes featured northwesterly and southwesterly integrated vapor transport (IVT) impacting western CO, characterized by a high frequency of anomalous landfalling West Coast Atmospheric Rivers (ARs) that penetrated inland facilitated by an upstream trough over the Intermountain West. Another cool‐season regime with southeasterly IVT impacting eastern CO was characterized by anomalous Gulf of America ARs facilitated by a trough and cut‐off low over the Great Plains. In contrast, a warm‐season regime is influenced by IVT from Gulf of America ARs facilitated by the North Atlantic subtropical high and the North American Monsoon circulation, impacting southwestern and southeastern CO. Representative storm examples from each regime are highlighted to examine the processes and impacts of top‐decile precipitation. These regimes provide further opportunity to assess predictability associated with AR and non‐AR related precipitation extremes in CO.