Russians Hoarded Snow from Previous Winters for Sochi Games
In addition to the nearly 500 snowmaking machines that will be in Sochi, Sochi organizers have been literally preparing for the Winter Games in Russia's sub-tropical resort town by saving snow from previous Russian winters in case the machines cannot produce enough powder for the next two weeks.
Because the Winter Olympics are held in Sochi, which has a sub-tropical climate, organizers are making sure that they will be able to make plenty of snow in the resort town that Russians usually go to in order to escape the country's brutal winters:
If the weather doesn't deliver them the snow they need, or there simply isn't enough, they have over 400 fixed snowmaking machines installed at the resort, along with 27 mobile ones, fed by two huge water reservoirs. These will produce artificial snow for the slopes by blasting a mixture of water and compressed air above the slopes. This combination breaks up the stream of water into tiny droplets, which freeze into snowflakes before reaching the ground. If conditions aren't right for the water to freeze on its own, agents can be added to the water to give the ice crystals something to form on.
If that does not work, organizers have reportedly stored "710,000 cubic metres of snow from previous winter seasons, just in case":
This isn't like sticking a snowball in a freezer, though: That just results in a hard ball of ice, and it wouldn't be of much use for the ski slopes. This snow has been collected into stockpiles, stored high up in the mountains, under heavy insulating blankets. While a little unconventional, this is a perfectly reasonable idea for storing snow, especially over the summer.
After the Games, Russia intends use the technology in Sochi to extend skiing seasons to 180 days a year at some resorts.