Numerical modeling of hailstorms and hailstone growth. Part III: simulation of an Alberta hailstorm - natural and seeded cases

Abstract

The model simulation of the natural case produces a very good replication of the observed storm, particularly the placebo feeder cell. This is evidenced, in particular, by the high degree of fidelity of the observed and modeled radar reflectivity in terms of magnitudes, structure, and evolution. The character of the hailfall at the surfcace and the scale of the storm are captured nicely by the model, although cloud-top heights are generally too high, particularly for the mature storm system. Seeding experiments similar to those conducted in the field have also been simulated. These involve seeding the feeder cell early in its active development phase with dry ice (CO 2 ) or silver iodide (AgI) introduced near cloud top. The model simulations of these seeded cases capture some of the observed seeding signatures detected by radar and aircraft. In these moldel experiments, CO 2 seeding produced a stronger response than AgI seeding relative to inhibiting hail formation. -from Author