Response of Microphysical and Rainfall Characteristics to Cloud Seeding: A case study of widespread cloud seeding operations over Saudi Arabia

The Kingdom of Saudi Arabia (KSA) consists of arid and semi-arid climates with extremely low levels of daily rainfall. Cloud seeding is an exemplary alternative to enhance rainfall and thus increase the water resources in the region. The Regional Cloud Seeding Program of the National Center for Meteorology was initiated in 2022 to address this issue through glaciogenic and hygroscopic seeding of convective clouds over the southwest and central parts of KSA. However, to understand and improve the effectiveness of cloud seeding, it is essential to analyse the rainfall characteristics and cloud microphysical processes in the region. Given the unique combination of dry and hot background conditions, analysing their response is particularly important due to their sensitivity to any seeding activity in the region. High resolution numerical simulations are performed using the Weather Research and Forecasting model (WRF4.6) to investigate the microphysical and rainfall characteristics of convective clouds. Valuable data derived from research aircraft used for validating the simulations and understanding cloud microphysical process. The study emphasizes the sensitivity of rainfall enhancement to model configurations on microphysics schemes during a widespread seeding activity over the southwest and central parts of KSA.