Link: http://money.cnn.com/2005/08/25/Autos/niss...nnons/index.htm

Noise from Nissan factory: cannon fire?
Reports: Car maker using "hail cannons"at Mississippi factor. Neighbors annoyed.
August 26, 2005: 8:58 AM EDT


NEW YORK (CNN/Money) - Nissan has been angering some neighbors of its Canton, Miss., auto manufacturing plant with its noisy attempt to change the local weather, according to news reports.

Concerned that hail storms could damage the paint on newly manufactured cars, the company has been using "hail suppression cannons," which send a loud sonic blast into the air above the factory, according to recent stories in the Jackson, Miss., Clarion Ledger and in the industry newspaper Automotive News.

The system is supposed to protect about 12,000 brand new vehicles, worth about $400 million, parked in the factory's shipping yard, according to a Nissan spokeswoman quoted in the Clarion Ledger.

The cannons' blast is about 50 decibels, according to a Nissan engineer quoted in the Clarion-Ledger. That's similar to the noise level near a highway, the engineer said.

Theoretically, the system prevents hail over an approximately 1-mile radius by vibrating water droplets in the air that form hail. Vibrating the droplets supposedly disrupts the hail-forming process, preventing hail storms.

The cannons are connected to equipment that detects weather conditions under which hail can form and they are supposed to fire automatically as needed, according to the Clarion-Ledger.

A National Oceanic & Atmospheric Administration scientist quoted by Automotive News said there is no scientific evidence that hail cannons actually work.

An engineer with Nissan insisted that the hail cannons are working and that people at the Nissan plant have seen evidence of hail in the area, but not over the plant, according to Automotive News.

Nissan's Mississippi neighbors should be pleased that the company has at least fixed the cannons so they will no longer fire continuously regardless of wether hail conditions are present, as they had been doing, according to the Clarion-Ledger report.

I've never heard of hail cannons before, interesting. You would think that they could put them undercover somewhere, but I guess the plant must not be big enough to store them all.

Hail cannons fall is a bit like cloud seeding in that it certainly pans out in theory but not so much in practice. Hail can also be very sporadic and localized, so the claim that it didn't hail on Nissan grounds could be true but not accurate as per this scenario.

slap a damn roof over them, sheesh