The targeted distribution of silver iodide can cause a thundercloud which transports hail, to rain prematurely. This is known as cloud seeding. The hailstones are thereby interrupted in their formation and enlargement. Ideally, they will have completely melted by the time they reach the ground.
It goes without saying that these measures can drastically reduce hail damage to land and infrastructure. Accordingly, more and more insurance companies are interested in this type of prevention.
A rain rocket functions in the same way. It is used in places where, although rain clouds are present in the sky, the climatic conditions for rainfall are lacking, e.g. in Namibia.