Mesoscale convective systems (MCSs) with larger rain areas and higher rainfall intensity than non-MCS events can produce severe flooding. Flooding occurrences associated with MCSs in the central US are examined by linking a high-resolution MCS dataset and reported floods in the warm season (April-August) between 2007 and 2017. MCSs are found to account for the majority of slow-rising and hybrid floods, while non-MCS rainfall explains about half of flash floods in July and August as individual thunderstorms occur frequently at the eastern foothills of the Rocky Mountains. The event-total rainfall area of MCSs is the dominant factor of flood occurrences: MCSs with greater rainfall areas tend to produce more floods. While not favoring more floods, propagating MCSs tend to produce flash floods with longer durations. These established links can improve our confidence in interpreting flood risks and their future changes due to changes in MCS characteristics with warming.
Published: August 1, 2021
Citation
Hu H., Z. Feng, and L. Leung. 2021.Linking flood frequency with mesoscale convective systems in the central US.Geophysical Research Letters 48, no. 9:e2021GL092546.PNNL-SA-159138.doi:10.1029/2021GL092546