CBC News - Calgary - Calgary hail shrunk by cloud-seeding planes

The Monday storm that pounded Calgary with hail the size of golf balls would have been even more severe if cloud seeding planes hadn't been in the sky earlier in the day, says an official with the company that flies the aircraft.

Just before the hail hit the city, Weather Modification Inc. had two airplanes in the air, seeding the clouds with shots of silver iodide, which shrinks the ice stones, said Tom Walton, the company's field program manager.