Snow and Weather Forecasting for Skiers
Why Ski Forecasting Is Different from Ordinary Weather
A weather forecast telling you it will snow 30 cm in the Alps this weekend means almost nothing without context. Where at the resort will that snow fall? At what altitude does rain become snow? How will the wind distribute it — or remove it entirely from the ridgelines? What base already exists, and will the new snow bond to it? What will the sky look like on the following morning when you want to ski it?
Skiing is peculiarly sensitive to weather parameters that ordinary forecasts either omit or bury. Temperature at a specific elevation matters more than the valley temperature reported on national weather services. The freezing level — the altitude at which air temperature drops to 0 C — is the single most useful number for planning a ski day, because it divides the mountain between rain and snow, between soft consolidated snow and slush, between good edge hold and ice. Learning to find and interpret that number transforms how you plan trips.
Freezing Level: The First Number to Find
The freezing level is published in every professional mountain weather forecast. In Europe, services such as Meteo France, MeteoSchweiz and Zamg Austria include it explicitly in their resort bulletins. In North America, the National Weather Service and specialist sites such as Mountain Forecast publish it by peak or summit area. Dedicated ski forecast services — Snow-Forecast, Windy's mountain layer, OnTheSnow — display it prominently because their audience understands its significance.
A freezing level of 1800 m at Verbier (base 1500 m, peak 3300 m) means that a third of the ski area is in rain or wet snow. The same freezing level at a lower-elevation resort such as Kitzbühel (base 760 m, peak 2000 m) puts virtually the entire ski area in thaw-like conditions. Conversely, a freezing level of 3500 m in late season opens the high-altitude glacier terrain at Zermatt or Val Thorens to warm, stable spring conditions with firm corn snow in the morning.
Crucially, the freezing level moves through the day. A level that sits at 2200 m at dawn may rise to 2600 m by early afternoon. This is why spring skiing rewards early starts — the corn snow that is perfect at 8 a.m. becomes wet, adhesive slush by noon on many runs.
How to Read a Snow Forecast
Snowfall forecasts are expressed in centimetres of new snow at a given elevation over a given period. The elevation qualifier matters enormously. A forecast of 40 cm at summit (typically 2500+ m) and 20 cm at mid-mountain (typically around 1800 m) means the upper mountain receives double the lower. This is the inverse altitude gradient that skiers use when chasing powder: high-elevation resorts such as Les Arcs 2000, Saas-Fee or Obergurgl consistently receive more snow and hold it longer than valley-based alternatives.
Snow water equivalent (SWE) rarely appears in public ski forecasts but underlies all of them. Light, cold snow at minus twelve degrees might produce 40 cm of accumulation from 4 cm of water; warm, wet snow at minus two might produce only 8 cm from the same water. This is why a heavy snowfall during a warm period feels dense and unsatisfying, while a lighter fall on a cold day skis far above its measured depth. When a forecast quotes snowfall at relatively high temperatures — within two or three degrees of freezing — mentally discount the skiing quality relative to the headline centimetre figure.
Snowfall timing is as important as total. Three centimetres of snow falling steadily over 12 hours and then stopping at midnight means excellent groomed pistes the next morning once the machines have worked overnight. The same 3 cm falling in a 45-minute burst during morning lift hours means zero visibility, a ski patrol closure review and inconsistent coverage. Good forecasts specify hourly distribution, not just totals.
Wind: The Variable That Overrides Everything
Experienced powder hunters know that the day after a storm is often better than the storm day itself, for exactly one reason: wind. During a heavy snowfall, exposed ridges and open bowls at resorts from Chamonix to Whistler Blackcomb are scoured by wind that deposits the same snow into sheltered terrain features. A northeast wind at Verbier piles snow into the southeast-facing slopes below the Col des Mines. A northwest wind at Méribel fills the trees below the Combe de Vallon.
Reading wind direction in a forecast tells you where the deposits will form. Wind speed tells you whether the snow will be lightly deposited and remain skiable as powder or will be violently compacted into dangerous wind slab. Wind speeds above roughly 50 km/h at summit elevation typically create wind slab conditions rather than skiable powder in exposed locations. Windy.com's mountain layer and the European Centre for Medium-Range Weather Forecasts (ECMWF) model, visible on weather-professional tools, give the best wind forecasts at mountain elevation for planning purposes.
Above-tree-line resorts are most vulnerable to wind redistribution. A resort like Tignes, with much of its skiing above 2400 m on open glacier and shoulder terrain, will have dramatically different snow conditions in different sectors depending on the previous storm's wind direction. Tree-skiing terrain at resorts like Fernie in British Columbia or Les Arcs in France is far more wind-neutral and holds powder in a wider range of storm types.
Temperature Trends and Snow Consolidation
Fresh snow consolidates rapidly under its own weight and, more so, with temperature oscillation. A pile of new snow at minus ten degrees will ski like light champagne powder for 24 to 48 hours and then sinter — the crystals bond to each other — into a denser, more supportive but less fluffy texture. Knowing the post-storm temperature forecast allows experienced skiers to decide whether to ski powder immediately or whether the snow will improve by consolidating slightly.
Persistent cold, such as the sustained minus fifteen-degree periods common at Alta, Utah, or in the Japanese Alps at Niseko, keeps snow dry and skiable as deep powder for days after a storm. The same storm arriving at a resort near the freezing point — say Villars in Switzerland or Heavenly at Lake Tahoe — may consolidate overnight to sticky, dense snow that skis more like wet cement than powder. The temperature trend over the 48 hours following snowfall is a better predictor of ski quality than the storm totals alone.
Isothermal conditions — where the temperature through the snowpack is uniform and near freezing — are the enemy of powder skiing and a precursor to wet avalanche risk. Forecasts from avalanche centres including the European Avalanche Warning Services group and the US Avalanche Center explicitly warn of this. Skiers with backcountry ambitions should treat any isothermal forecast as a signal to stick to groomed terrain.
The Best Forecasting Tools for Skiers
General-purpose weather apps are typically inadequate for ski planning because they show point forecasts at valley elevation rather than at ski-relevant altitudes. The purpose-built alternatives are significantly better.
Snow-Forecast.com publishes six-day snowfall forecasts for several hundred resorts globally, with separate columns for summit, mid-mountain and base elevation. It is the most widely used tool among ski professionals for trip planning. Mountain Forecast provides similar summit-focused data and includes the temperature profile.
Windy.com, with the ECMWF or GFS model selected and the mountain layer enabled, allows visual tracking of precipitation and wind at different altitude levels across a full mountain range. It takes 20 minutes to learn and repays the investment many times over for anyone travelling to ski.
For avalanche-relevant weather, the local avalanche bulletin — published daily by Avalanche.org in North America and by regional services in Europe — includes snowpack analysis and recent snowfall temperature profiles that are nowhere else available publicly. Reading the current bulletin before any off-piste skiing is a non-negotiable habit.
Turning Forecast Data into Trip Decisions
The practical chain from forecast to decision looks like this: check the freezing level for your skiing days; check the six-day snowfall by elevation at your resort; check the wind direction and speed during and after any forecast storm; check the post-storm temperature to gauge powder duration; look at the avalanche bulletin if you plan to ski any uncontrolled terrain.
Open the map to identify which resorts in your target region sit above the forecast freezing level, then use the tools above to find where the storm snow will land and how long it will last. That combination — elevation, snowfall, wind and temperature — is what separates a planned powder day from a lucky one.