Co‐Occurring Atmospheric Features and Their Contributions to Precipitation Extremes

Abstract Object‐based identification algorithms for atmospheric features are commonly utilized to attribute global precipitation. This study employs a systematic approach to examine feature co‐occurrences and their relationships to mean and extreme precipitation. Four features are identified using existing data sets for atmospheric rivers (ARs), mesoscale convective systems (MCSs), low‐pressure systems (LPSs), and fronts (FTs). Often, a single atmospheric phenomenon satisfies the criteria set by multiple feature identification algorithms, yielding an association between precipitation and multiple features. Over the extra‐tropics, the number of features attributed to a single event typically increases with precipitation intensity. Over two‐thirds of the precipitation is from co‐occurring features, with a considerable fraction related to AR‐FT co‐occurrences. Over the tropics, about one‐quarter of precipitation is associated with co‐occurring features, with LPS‐MCS co‐occurrences contributing substantially in monsoon regions. MCSs are the leading single‐feature contributors over tropical land and oceans. In the extra‐tropics, FTs, ARs, and their co‐occurrences account for over half of the total precipitation over oceans. AR‐FT‐MCS and FT‐MCS co‐occurrences contribute to extremes (precipitation exceeding the 95th percentile) over both oceans (over 30%) and land (over 20%). Any combination of features involving MCSs shows a larger contribution to high percentiles of precipitation intensity. A case analysis indicates that AR‐FT‐MCS co‐occurrences exhibit convective instability and deep vertical motion, suggesting that the feature trackers and reanalysis are capturing physics relevant to both convective and frontal systems. The results here emphasize the need for simultaneous identifications of multiple features when attributing precipitation to atmospheric phenomena.Plain Language Summary This research study examines how different types of weather systems contribute to global precipitation. Instead of studying individual weather systems separately, the study investigates how frequently these systems occur together and how that impacts precipitation. Identification algorithms have been used to pinpoint these co‐occurring systems. The findings indicate that co‐occurring systems are more prevalent over mid‐latitudes than the tropics, and highlight specific weather combinations that significantly contribute to heavy precipitation. For extreme precipitation, combinations such as atmospheric river‐front (FT)‐mesoscale convective system (MCS) and FT‐MCS are vital over oceanic and land regions, respectively. The findings emphasize the importance of simultaneously identifying multiple features to enhance understanding and prediction of rainfall patterns. Additionally, combinations involving MCSs contribute significantly to high percentiles of rainfall intensity. Extra‐tropical MCSs are associated with greater convective instability, as observed in the tropical MCSs.Key Points Global precipitation variability linked to atmospheric features is systematically analyzed for their co‐occurring instances Contributors to total/extreme precipitation in the tropics and extra‐tropics are highlighted, with the latter dominated by co‐occurring features Features involving mesoscale convective systems have a larger contribution to high percentiles of precipitation intensity