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So you’ve heard that ski resort can make snow, and you might be wondering: so what’s it like? Can you tell the difference when you ski on it? Great questions and here’s the answer:
Man-made snow is snow, it’s just made by snowmaking machines pumping water droplets at high speed through a condenser, rather than naturally falling from the sky. Natural snow has a complex crystalline structure whereas snow from snowmachines is simple frozen fragments.
It’s good to ski on and most skiers would not be able to tell the difference between a groomed slope that has machine snow and one that’s all natural -- unless that is you compare it to fresh powder.
*Fake snow or dry ski slopes are different surfaces -- they’re not snow.
**I use the word ‘snow guns’, ‘snow machines’ and ‘snow cannons’ interchangeable below -- it’s the same thing.
What is it like to ski on machine snow?
Skiing on machine-made snow pumped from canons is fun and similar to skiing on natural snow, but it is denser and a tiny bit rougher to ski on and does pack down into ice faster.
Most ski runs are a mixture of natural, weather-made snow and machine-made snow, so the final makeup of the ski run is usually blended together over time (unless you ski directly below a ski canon that is blasting out ice crystals).
Snow from snow guns is still cold, wet and very snow-like. It’s not until you look a bit closer that you see how the crystalline structure is quite different.
NASA scientist Dr. Peter Wasilewsk looked at machine snow and natural snow under a microscope to see the difference. As you can see in the image above, natural snow on the left is more delicate and complex. This structure makes it lighter and fluffy when it’s freshly fallen -- but also easier to break.
The image on the right is machine made snow which is made of more simple clumps of ice and more closely resembles snow after it has been packed down by other skiers.
This difference in structure makes it denser, which is great for ski racers on downhill events who want a hard almost icy surface (race courses are injected with more water and packed down much harder unlike normal groomed pistes) for their sharp edges and ambition to go as fast as possible.
For powder lovers, there is nothing like the real thing, although without snowmaking machines many ski resorts would not be able to open early or stay open when the weather doesn’t provide. [Snow machines have become so popular that over 90% of U.S. ski resorts now have them installed, source.]
Machine snow is wetter (typically twice as wet) than natural snow which makes it lump together faster. Because natural snow is drier, you’ll feel lighter and more buoyant as you ski through it compared to the wetter machine snow (source).
One major benefit of artificial machine snow is that it lasts longer (great for ski competitions) and is more resistant to rain, making it a good base for natural snow to fall onto.
If it rains, machine snow is more likely to hold together for longer (less fragile) but it also gets slushier faster because of the already high water content.
Snow-making snow is said to be like two-week old natural snow. It’s got a very high water content, it’s very dense, it lasts longer than natural snow when the sun is beating on it because of the high water content.
Mark Meyer, Squaw Resort
However, the truth is most skiers (especially new skiers) won’t be able to feel the difference between a groomed ski run made entirely of natural snow and another made predominantly from machine snow. That’s because groomed pistes are compacted by other skiers and snowplows, and so the surface on both will feel pretty similar.
Once it’s been cut up and groomed by the machines, no one can tell.
Richard P, Manager at Peisher Ski Resort
If you had two slopes and one was virgin untracked powder and the other fresh canon snow (and you momentarily hid the machines and somehow leveled it out without compacting it), then the average intermediate skier would likely feel the difference.
All said, there are different types and qualities of natural snow and machine snow and the final texture depends on the humidity and temperature as it forms and onto what base snow it comes into contact with.
If you’re interested, I just wrote an article all about the different snow you’ll find on the mountain here: Skiers Guide to Different Types of Snow
How is natural snow made?
Natural snow develops when water vapor in clouds freezes and falls to the ground. Snowflakes are made up of hundreds of these frozen crystals that form around small specs of dirt in the air.
Snowflakes grow in complexity and size as they fall to the ground and take on wonderfully unique structures. Yes, it’s true: every snowflake is different -- that’s because each snowflake charts a unique course through different air currents that effect on a microscopic level how the crystalline structure grows.
Once fallen snow can take on many forms, starting off as fresh powder and turning to crud, packed, concrete and various other forms of snow that skiers know it as.
How is artificial snow made?
Artificial snow is made by pumping millions of tiny water droplets into the air so they freeze and fall to the ground.
There are two main types of snowmaking machines -- one that uses compressed air and water and the other that uses a fan and water -- both atomize water. Snow machines use nucleators (like Snomax) that they inject into the water to increase snow products. like Snomax.
Snomax is a made from freeze-dried bacteria commonly found on the leaves of plants (source). Like natural snow, this provides a spec of matter for ice crystals to more quickly form around each droplet. The end result is more snow from the same amount of water at warmer temperatures.
#1 Compressed air
This type of machine uses the compressed air to fire the water at very high speed, splitting it up into tiny particles that travel further across the slope.
- Pros: Travels further, less electricity.
- Cons: You need two inputs.
#2 Fan snowgun
This type of machine uses an electric fan to blow the stream of water into drops. Also known as an airless snowgun.
- Pros: Doesn’t require compressed air.
- Cons: Requires more electric power.
Operating Temperatures 🌡
Snowmachines can’t run all the time and they need to be within a specific temperature to work. Technically machines start to work below freezing (and sometimes above, more on that below) but a more efficient temperature is -2°C (28°F) or below when more snow can be produced and it is less at risk of melting as soon as it is made.
On a warmer day, snowmaking machines can be set to make smaller droplets so more of them freeze (but this does make a smaller pile of snow). While on a colder day the droplets can be lager to make more snow.
It can get too cold for snowmaking machines to operate, and if the machine is running below -20°C+ (-2°F+) and the water stops because of a power outage, the pipes can freeze, explode and destroy the expensive machines.
However colder temperatures are always better for snow production.
The temperature is not the only factor, in fact, humidity is just as important when it comes to the amount of snow that can be made.
Snowmakers use the wet-bulb temperature (WBT) to determine whether they can operate a machine or not. The WBT is the temperature read by a thermometer covered in a water-soaked cloth plus moving air (source) -- similar to what the water droplets experience as they are thrown from the cannon.
It’s essentially the temperature and humidity combined. Snowmaking machines can operate even at high temperatures -- up to 4°C (40°F) -- but with low humidity (source).
The lower the humidity the more snow can be produced per hour. The ideal humidity is less than 30% but ideally when it’s in the low teens. Snowmaking is more efficient in low humidity (when the air is less saturated with water) because water cools faster (source), therefore making larger snow crystals from each droplet.
The best weather for snow production is cold and dry.
There’s more to snowmaking than placing cannons around the resort. A whole host of hidden infrastructure needs to be set up to feed water, electric and pressurized air to the snow systems.
You need massive amounts of water and electricity to power snow canons and it’s said that on average 50% of an average American ski resort’s energy costs come from snow production (source).
It takes about 401 liters (106 gallons) of water to produce one cubic meter (35 feet³) of snow. The average snowmaking machine makes that much snow in 1 minute! (source).
Although 80% of water used eventually ends up at its source once the snow melts, it can limit the amount of water for communities lower down the mountain and have some environmental consequences to the area (source).
1-14kwh per cubic meter of snow depending on the conditions and the efficiency of the machine (source). All this electricity goes to power the pumps, the fans and the pressure jets.
Computer systems 💻
Hi-tech computer systems are often installed to constantly monitor humidity and temperature and adjust the pressure to maximise snow conditions.
It takes a skilled workforce to manage the machines, keep them running, move them around the slopes and a small army of snowplows to spread out the snow.
How much does it cost to make snow? 💰
There’s no mistaking, snowmaking is very expensive. It costs between $1-2,000 to cover one acre (4046 meter²) with 12 inches (30cm) of snow (source). Although it’s still cost-effective otherwise ski resorts wouldn’t invest so heavily in snowmaking technology.
The organization Protect Our Winters estimates that the ski industry would suffer a loss of $1,07 billion per year without being able to make their own snow. That’s because they can open early, stay open for longer and hold ski competitions.
With the ski season being only 5-6 months, each ski day the resort can stay open, the more revenue they can generate. That is up until spring and early summer when visitor numbers drop off and many resorts will close even when there is enough snow to stay open.
Behind the Scenes
This is a cool video showing the technical art of snowmaking at Calabogie Peaks Resort.
Snowmaking & Global Warming
According to the European Environment Agency, since 1970 the length of the snow season in the northern hemisphere has decreased by five days each decade (source).
The Rocky Mountains, for example, have lost 20% of their spring snowpack.
The latest statistics published in 2016 show that over the period from 1967-2015 snow cover has decreased by 7% on average in March and April and by 47% in June. In Europe specifically, the numbers are even more worrying (13% & 76%).
This is a worrying trend and means the demand for artificial snow is only going to increase. Hopefully, advances in technology can make for more sustainable and less energy intensive snowmaking -- otherwise, the environmental cost and the cost of ski passes is going to rise.
As much as we’d all love to only ski on natural snow, snowmaking is now, unfortunately, an integral part of skiing.
P.S If you’re worried about skiing on machine-made snow, don’t be it’s pretty much like skiing on a groomed piste.