The contribution of local evapotranspiration (ET) to precipitation has been called “moisture recycling” and studied using bulk models assuming a complete mixing of local ET within the atmospheric column. The latter is inconsistent with the entropy conservation perspective of a climatologically slanted and layered structure of air movement across latitudes. Reconciling the two views requires an understanding of overturning and mixing associated with different weather systems. In this study, we aim to better understand moisture recycling associated with mesoscale convective systems (MCSs), which are ubiquitous and play an important role in regional and global water cycles. Using WRF enhanced with water vapor tracers (WRF-WVT), we perform a convection-permitting simulation and use the WVT to tag moisture from local ET in the Southern Great Plains in May 2015, during which more than 20 MCSs occurred and produced significant flooding. Water budget analysis reveals that the majority of local ET is advected northward, while ~30% of local ET is “pumped” into the upper troposphere and contributes to ~10% MCS precipitation. By focusing on 5 MCS events that are less influenced by synoptic disturbances, we find an upright “pumping” of local ET at the MCS initiation and development stages. The ET-sourced moisture diverges into two branches in the upper troposphere at the MCS mature and decaying stages. One branch advects the local ET moisture downstream due to strong upper-level wind shear, while the other branch contributes to the trailing stratiform precipitation. We also find that moisture recycling peaks during early night hours (18 LT to 12 LT) due to ET accumulation during the daytime and concurrent mixing driven by active convection. Therefore, our analysis depicts a pumping mechanism associated with MCSs that mixes local ET vertically. The pumping provides one possible pathway depicting how local ET contributes to precipitation processes, while highlighting the importance of MCSs in water cycle by boosting moisture recycling through mixing of moisture upward.