In some countries in Europe, 20 years ago existed very effective hail suppression system. It is still in place but there are some attempts to outlaw this practice (and I do not understand the reasons behind them.. because I know for sure the results were positive, being part of this during some time back in '80es)
C-band radars from WWII were used to locate the cores inside the clouds (where the ice was) then those areas were seeded with silver iodide crystals, delivered by two stage rockets (
http://en.wikipedia.org/wiki/Cloud_seeding).
Hundreds of rockets were used in each campaign.. but the damage I am seeing here in Oz almost never happened (except in areas where rocket were not fired - for example if people who were supposed to operate rocket launchers were too busy else where (in local pub, for example).
Mainly the system was established to protect crops during the summer time (July, August, September) when hail is very common.