Snow guaranteed for Turin Olympics

Unpredictable Alpine weather has prompted Olympic organisers to install 10 state-of-the-art snowmaking facilities to ensure perfect pistes

Atomisation: 
High- pressure cold water released as fine droplets

Evaporation
Droplets cool and expand with change in pressure 

Convection: 
Fan cools and disperses crystals

Nucleation
Particles introduced around which droplets crystallize

SNOW CANNON: Dependent on temperature, humidity and wind condtions

Weather station

NATURAL SNOW: Form varies according to moisture content and temperature
Saturation

Plates: Man-made crystals have less time in air to grow – simple shapes form dense, granular snowpack

Dendrite: Forms at just below 0˚C in supersaturated air, or -20 to -25˚C in lower humidity

Most complex structures formed by crystals falling over longer period

Hollow prisms
Fine, granular snow

Solid prisms
Moisture-starved, low temperature crystals

Needles
Solid plates
Thick plates
Sector plates

Natural powder snow forms in low humidity – extreme cold preserves crystal structure to retain light, fluffy texture

TYPICAL CLOUD SATURATION
-10˚C
-20˚C
-30˚C
-40˚C

Sources: TechnoAlpin, USGS
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