Nissan fires cannons, disturbs nearby residents

Those who live near a car plant should expect a bit of extra noise, but what about cannon fire? Nissan has been firing cannons into the sky over its Canton, Mississippi plant, as Civil War re-enactment grows in popularity. I'm just kidding, of course, but the real reason is just as implausible to me - it's to prevent hail. Supposedly, the $400 million system (probably another example of getting ripped-off at a gun show) system causes water droplets to fall out of suspension in a one-mile radius, thereby preventing hail from forming and causing massive sheetmetal damage to the completed vehicles parked outside the plant. Lending to the residents' complaints was the fact that the system continued to fire regardless of the weather. I'd like to hear the opinions of any weather geeks in the audience, as I consider myself a minor expert in creating loud noises of the Magnum variety, but I've never really studied the effect of such things on local weather conditions. Regardless of its effectiveness on hail, it apparently doesn't work on hurricanes.