Numerical Simulation of the Cloud Seeding of a Warm Base Illinois Convective Cloud with and without Ice Multiplication Active

Seeding simulations on a moderately vigorous, warm base, convective cloud produced a strong initial signal if ice multiplication was not active; no signal otherwise. Even though a strong effect was produced in the initial graupel field, no effect on the total rainfall was produced. The results lead to speculation about the effects of hygroscopic seeding of continental, cold base clouds. The large drops formed by the seeding could establish an ice multiplication process leading to cloud ice (and the resultant precipitating ice) at temperatures even higher than those due to ice-phase cloud seeding (such as silver iodide).