Snow grooming at Perisher

4 September 2023

Snow Grooming at Perisher

Anyone who experiences first tracks is familiar with Perisher's well-established reputation for corduroyed perfection. Responsible for smoothing out all the lumps and bumps from the slopes each night is Perisher’s highly skilled grooming team; a crew of around 40 during the winter. Perisher’s fleet of snow groomers (or snow cats) is the largest in Australia!

Importance of snow grooming for skiing and snowboarding holidays

Snow grooming ensures guests are provided with safe and high-quality skiing and snowboarding regardless of conditions. It is a combination of high-quality groomed slopes and ungroomed off-piste slopes that provide our guests with the best possible skiing and boarding experiences.

Changing snow conditions have a massive impact on a skier or boarder's day. Temperature and atmospheric conditions create anything from dry powder to soft hail, each presenting different problems for slope preparation. For example, fresh snow contains ice crystals that are linked together and contain a lot of air. Snow grooming compresses and packs down the fresh snow, removing much of the air and creating a load-bearing surface suitable for skiing or boarding.

During the day, as skiers and boarders make turns on the slopes, snow is pushed downhill and to the side, creating piles of snow or moguls. Each night during the winter, Perisher's fleet of snow groomers travel up and down the slopes moving, flattening and packing down the snow creating a high quality skiing and boarding surface ready for the next day.

The work done by our snow grooming team is vital in maintaining the high quality of terrain at Perisher. The corduroy finish formed by the groomer's tiller is just the end product of many tasks performed during the night. Some of these tasks include:

  • Smoothing out bumps and moguls.
  • Maintaining snow depth in high traffic areas.
  • Construction of competition mogul courses and race courses.
  • Reshaping and rebuilding trails.
  • Pushing out snow from snow fences and snow drifts.
  • Removing excess snow from around lift stations.
  • Covering creeks, rocks and other obstacles.
  • Spreading man-made snow.
  • Packing fresh snow.
  • Shaping the Superpipe.
  • Making interesting and challenging features in the Terrain Parks.

Snow fences, snow farming and good grooming techniques are as important as snowmaking when it comes to making a slope skiable throughout the whole season. Perisher prides itself on combining all snow conservation management techniques including extensive summer works to improve and increase snow retention, to provide guests with high quality skiing and boarding surfaces each winter day.

What is a snow grooming machine and how does it work?

Generally, a snow grooming machine has two large rubber and steel tracks that disperse the weight of the machine evenly across the snow surface and cut into the snow to assist with climbing. Mounted on the front is a multi-directional blade that cuts and levels the snow surface before driving over it. A power tiller on the rear churns the snow to an even consistency before a large, heavy comb then drags across the surface leaving a corduroy finish on the snow.

The ultimate snow grooming machine can climb steep slopes, push heavily compacted snow and leave a seamless trail of corduroy in its wake. Specialty machines can winch on extremely steep terrain and have attachments for carving perfect half-pipes and other features.

The blades, which are mounted on the front of the machines, have twelve movement capabilities: Up/Down, Tilt left/right: Curl or Crowd forward/back: Swing or Windrow left/right; Left Wing forward/back; Right Wing forward/back, which allows difficult-to-access snow to be groomed on the slopes as well.

Terrain Influences on your skiing and snowboarding

Perisher has a wide variety of terrain. Some areas such as Front Valley, Guthega, Smiggin Holes and parts of Blue Cow have been summer groomed to a high standard. This means that these areas can be easily groomed during the season and safely opened on a minimum depth of snow.

Other areas, such as Mt. Perisher, which has heavy rock, heath and vegetation, require a much greater depth of snow before they can be snow groomed and safely opened to the public. In these areas, the type of snow, as well as the direction it comes from, also influences when snow grooming can commence. These areas generally require heavy moisture laden snow to pack down the underlying heath and vegetation.

Wind and Snow Storm Influences

Wind is both our friend and enemy. We actively farm snow using over 10 kilometres of snow fences to collect snow. Snow fences create a low-pressure area on the leeward side into which snow falls and builds up. The snow that accumulates ("farmed snow") is then spread out so that the fences can again catch snow in the next storm.

When it is windy in exposed areas, especially in high traffic areas, every time anybody slides over the snow, it can blow away. This can sometimes be seen on wind-exposed break-overs where the base (an icy hard layer) has been exposed.

After snowstorms, the machines spend most of their time pushing snow from the "level sensitive'' lift stations, removing snow drifts and making sure the lifts will open on time. The amount of grooming can often be restricted to the priority beginner and intermediate areas, as the machines struggle to keep up with the storms effects. It can take up to at least 24 hours to get the grooming back up to the normal area standard after a storm. Poor visibility can also hamper grooming operations during storms.

Types of snow and different grooming requirements

Temperature, relative humidity, wind and other elements of the weather all combine to produce different types of snow that require different types of grooming.

The following tables outline some of the different types of snow that you may experience and some examples of the grooming requirements that are needed as a result.

Description Grooming requirements Finish
Light and fluffy easy to kick away. Consistency can remain the same throughout a 24 hour period if the temperature remains well below freezing point. A groomers delight unless it is too deep then it can be hard to climb. Easy to ride corduroy finish.
Hard Packed
Description Grooming requirements Finish
When natural or man-made snow becomes firmly packed. The snow has not melted and re-crystallised, but has been compressed through grooming, constant skiing or boarding, or continuous wind compaction. Easy to groom. Finish can be excellent providing a corduroy finish, although, this corduroy surface will generally revert again to hard packed as skiing and boarding activity increases and if there is a strong wind.
Spring snow
Description Grooming requirements Finish
In a 24 hour period spring snow will generally have 3 characteristics:

1. Early morning -
frozen hard packed.

2. During the day -
softening to wet slush or
dry loose granular snow.

3. Any time during the day
and night depending on
the temperature -
breakable crust.
Spring snow can be very hard to groom especially on steeper runs because of the limited traction available. Grooming can push the snow out either side causing ridges or berms to form between passes. Grooming uphill can help solve this but the limited traction and the downhill pass that follows can result in an unsatisfactory standard of grooming. This type of snow may also set in a thin layer on the surface (breakable crust). When the snow does this, it will feel like ice early in the morning, but will thaw fairly quickly. Grooming this type of snow can be difficult as the machines may break through the crust. Spring snow can lead to reduced grooming, an unsatisfactory finish, shortened slope life and snow loss. In order to conserve this type of snow, it is often preferable not to groom it at all until conditions improve. It can be difficult to get a good finish, for example machines can bog climbing uphill, leaving depressions in the slope and, when grooming downhill, the snow can roll away from the machine leaving large soft balls of snow laying on the slope that can later freeze. These can be a hazard to skiers/boarders. If slushy spring snow has not had a good overnight freeze, even a groomed slope can form moguls by 10 am. If groomed after it has frozen, the finish can be good.
Rain / fog affected snow
Description Grooming requirements Finish
Wet and soft to a deep depth, sinking underfoot. Behaves much like spring snow with the extra problem that grooming this snow can cause it to deteriorate at a much faster rate. If the snow melts after it has been groomed, the machines track marks can be left imbedded in the snow resulting in a hazard to skiers and boarders. As a result of these problems grooming is generally not carried out on rain and fog affected snow. Usually not good and has a similar finish to spring snow.
(See above.)

As a general rule, rain packed snow offers better skiing and boarding than trying to groom it with a machine.
Description Grooming requirements Finish
Not to be confused with hard packed. Ice has a hard, glazed surface created either by freezing rain, ground water seeping up into the snow and freezing, or by the rapid freezing of snow saturated with water from rain or from solar induced melting. It is important to note that, generally, hard packed snow is opaque whereas ice is translucent. Ice can be very difficult to groom especially if it is windy as the fine particles that are created by the machine can blow away very quickly. This leaves only the marks left by the blade or tiller. May require double or triple grooming passes. If multiple passes are required, this can dramatically reduce the areas able to be groomed overnight. Can be good if the wind does not blow the groomed surface away. Skiing and boarding can be hard and fast first thing in the morning. Spring skiing and boarding on the groomed slopes can be excellent provided the overnight freeze is strong enough to create a firm base.
Machine-Made Snow
Description Grooming requirements Finish
Generally the same as hard packed snow The current snowmaking coverage is 53.4 ha of the ski area. The grooming team must ensure that this man-made snow is flattened into a skiable slope before we open each morning. On very cold nights (-10c or colder), it can be quite a job because of the amount of snow that can be produced. Generally good, but by the time the skiers and boarders get onto the surface, it is usually the same as hard packed.

The Operators

During peak season, Perisher employs up to 30 operators, many having extensive experience in Australia and North America. We employ Australian operators as well as operators from some of the best-known resorts in the world, such as Whistler Blackcomb and Squaw Valley. Our operators are among the best in the world in this highly specialised field. North American resorts actively seek out our operators because of their skills and work culture.

Grooming is predominantly a night operation consisting of two shifts - 4pm to 12am and 12am to about 9am. In special circumstances, we may also groom during the day, but this is kept to a minimum for safety reasons.

During a winter season, the grooming fleet can log up between 12,000 and 15,000 hours depending on the season and groom approximately 33% of the 1,245 hectares of skiable area most nights (about 412 hectares).

A daily grooming report is available to the public each morning via Perisher’s website.

Snow groomer operators will tell of hair-raising experiences in whiteout conditions, in the dead of night when it was difficult to determine up from down, never mind the exact location. They will also speak of stars and moonlit nights, and inspiring sunrises from the top of Australia that make the night shift a privileged crew.

Perisher and its grooming staff hope this information helps you understand more about the challenges of grooming as well as the goals that are strived for. The groomer operators will be out there working all night seeking to provide the best surface for the best experience. Enjoy!