New snow, snow depth, snowfall level

Date: November 2026 · Reading time about 5 minutes

Three terms, three meanings

Snow depth is the entire snow cover, measured vertically from the ground to the surface – old and new snow combined. It is measured with a fixed snow level gauge or automatically by laser or ultrasound, always at a single point. In ski areas operators often provide two values for valley and mountain, and on prepared slopes the value can significantly differ from natural snow.

New snow is the snow that falls during a defined period, usually 24 hours. Austria’s Wasserkreislauferhebungsverordnung defines it as freshly fallen snow in the 24 hours before the observation. It is measured on a level snow measuring board, so that the older snow underneath does not count.

The Snowfall level is an altitude rather than an amount. Precipitation falls mainly as snow above it and as rain below. It generally lies below the freezing level, typically 200–400 metres in humid air and sometimes around 1,000 metres in dry air. It is a transition zone. Across a resort, it can separate snow at altitude from rain on the valley run.

Why the snow depth hardly rises

After a night with 30 cm of new snow, the snow depth the next morning is often only a part of that higher. This has several reasons:

• Settlement: Fresh snow is airy and collapses under its own weight, and the older snow underneath gets denser.
• Wind: Wind removes snow from summits and ridges and deposits it behind obstacles and in hollows. A measuring point may therefore receive much more or less snow than nearby terrain.
• Heat and rain: If the snowfall level only falls during the course of the event or rises again, part of it melts away immediately again.

New snow tells you what has just fallen. Snow depth helps you judge how much cover has accumulated, particularly on runs without snowmaking.

How models estimate new snow

Weather models do not predict snow in centimeters, but precipitation in millimeters - the water equivalent. One millimeter equals one liter of water per square meter. How much snow that turns into depends on how loose the snow falls.

The common rule of thumb is: 1 mm of precipitation yields approximately 1 cm of new snow. This corresponds to a new snow density of around 100 kg per cubic meter. However, the rule is only an average:

• In mild temperatures and wind, wet, heavy snow falls - from 1 mm, at most about 1 cm.
• In cold weather, dry air and calm wind, very loose snow falls - from 1 mm it can become 2 to 3 cm.

Furthermore, the amount of precipitation itself is already a forecast with uncertainty, as is the snow limit. Therefore, a statement such as "20 to 40 cm" is more accurate than "27 cm". And: A model value is not a measurement. What actually lies is shown by measurement stations and the snow reports of the operators.

That's how Kaiserwetter Ski calculates

Kaiserwetter Ski uses this rule of thumb and rounds estimates above 10 cm to the nearest 5 cm, marked with ~. In Austria, recent snowfall is calculated from GeoSphere Austria’s INCA analysis, and forecast snowfall from model precipitation and the snowfall level. These are estimates. The app also shows the snow-depth trend in Austria and the freezing and snowfall levels for each resort.

For favorites there is a new snow announcement (Powder Alert from 20 cm) and a note on a First-Tracks day after new snow with a clear morning.

Free in the App StoreKaiserwetter Ski

What makes powder snow different

Powder snow is colder, drier and fluffier new snow with a lot of air between the crystals. It forms mainly when it snows at low temperatures and with little wind – that is exactly when a millimeter of precipitation turns into more than a centimeter of snow.

Powder changes over time. Wind can turn it into cohesive wind slab. Sun and warmth make it wetter and heavier, and subsequent cooling can form a crust. It often lasts longer on shaded north-facing slopes and at higher elevations.

Wind redistribution

Wind is the great builder of the snow cover. On the windward side (Luv) it blows snow away, so domes and ridges are often blown off, hard or even bare. On the leeward side (Lee) it deposits it again: behind ridges, in gullies, depressions and on terrain edges. There, waves and bound snow layers form – the Wind slab.

Wind-blown snow is one of the five typical avalanche problems. It can be soft or hard and is always bound: if it breaks, a whole snow slab can slide away. Not for nothing is “loose snow and wind” one of the ten danger patterns with which the warning services in Tyrol, Bavaria and South Tyrol work. Where the fresh wind-blown snow accumulations are located, the official avalanche bulletin with elevation and exposure describes – more about it at Avalanche warning levels explained.

For skiers, this means very practically: After a windy snow night, one side of a slope can be deeply snowed and the other icy. Outside of secured slopes, wind slab is one of the reasons why the avalanche bulletin is a mandatory reading.

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