Assessment of the GPM IMERG Product in Estimating the MCS Precipitation over the Central and Eastern United States

This study investigates the seasonal variability of mesoscale convective systems' (MCSs) precipitation over the central and eastern United States from 2014 – 2016. A satellite brightness-temperature-based algorithm is employed to identify and track the MCSs during this period. Utilizing the NEXRAD Q3 and Stage-IV analyses and satellite-based GPM IMERG product, the precipitation properties of identified MCSs are studied for four different seasons: spring (MAM), summer (JJA), fall (SON), and winter (DJF). Based on the tracked MCSs, the precipitation properties such as precipitation intensity, total rainfall amount, spatial distribution, and rainfall diurnal cycle are statistically investigated for each season. Differences between stratiform and convective components of the MCSs’ precipitation are also studied. The MCSs' characteristics, such as lifetime, areal coverage, occurrence, and propagation speed of identified systems are examined as well. This study reveals the seasonal variations of MCSs characteristics and their associated precipitation properties, and further examines how these properties are related to the generating mechanisms (i.e. local forcing, large scale dynamics) during different seasons. Through integrated analyses from both radar- and satellite-based precipitation products, the differences between different precipitation products, and their potential limitations, are revealed as well.