Severe weather events are often associated with mesoscale convective systems (MCSs) (Breugem et al., 2020;Doswell et al., 1996;Maddox, 1980). The characteristics of MCSs causing rainfall events in East Asia are different from those in the United States (Hong, 2004;Sohn et al., 2013). In the United States, MCSs often develop in dry continental environments with high convective available potential energy (CAPE). Intense vertical velocities and hailstorms characterize such MCSs. In East Asia, MCSs develop in moister environments associated with the East Asian summer monsoon (Yokoyama et al., 2014).MCSs in moist environments are characterized by a slantwise ascending deep inflow (layer lifting) and a moist absolutely unstable layer (MAUL) (Bryan & Fritsch, 2000;Houze, 2004Houze, , 2018. The MAUL forms when destabilization by saturation is faster than the release of instability by buoyancy (Bryan & Fritsch, 2000). Environments favorable for the organization of MCSs with layer lifting are characterized by high moisture contents above the boundary layer, moderate CAPE, and strong low-level shear with low-level jet (e.g.,