Forecast information

Sources and methodology

How the forecasts are produced, which sources they use, and what data is unavailable.

The forecast

SnowSays processes public Environment and Climate Change Canada (ECCC) weather model files on a server operated by Halabuda Labs. SnowSays publishes one canonical forecast document for each resort, combining its mapped-elevation snowfall and weather. Canada Ski Hols reads the same SnowSays documents for its five forecast resorts, so values and update times remain identical on both sites. Those Canadian resorts retain the HRDPS, REPS and GEPS forecast originally developed for Canada Ski Hols. The other 95 resorts use GEPS, a 21-member global ensemble, on its 0.5-degree output grid. No commercial weather API is used for these snow forecasts. Snow depth equivalent uses a fixed 10:1 snow-to-liquid ratio. Actual fresh-snow depth varies with density, wind and terrain.

Worldwide coverage

The directory contains 100 resorts in 20 countries across 5 continents. This is a selected international set, not a complete list of ski resorts. Global-model forecasts use complete six-hour accumulation periods and separately calculated 24-hour totals. Temperature and wind are six-hour samples of the ensemble median, not continuous measurements or period extremes.

Elevation matters

SnowSays caches a separate MET Norway forecast for every registered Base, Mid and Upper mountain point, including its mapped ground altitude. MET Norway uses that altitude to adjust temperature. Sky and wind remain point-model guidance. ECCC remains authoritative for rain, snow and new-snow amounts; SnowSays does not manufacture snowfall from a temperature correction.

Worldwide GEPS snowfall still uses a 0.5-degree grid, so several elevations can share one snowfall cell even though their MET temperatures differ. ECCC cloud cover and pressure-level temperature profiles are being retained as validation fields and are not promoted automatically.

What a range means

Ensemble ranges represent the 10th–90th percentiles of model snowfall totals. They are uncalibrated model spread, not a validated probability interval. We never add hourly percentiles or fill missing snowfall with zero.

Accuracy and freshness

Local snowfall verification is not yet available. We do not claim a measured accuracy score. If a refresh fails, SnowSays keeps the last validated forecast available for up to 14 days and marks it as delayed with its unchanged issue and expiry times. The system never extends timestamps or presents stored guidance as a new model run. Every accumulation has an explicit time window in the resort’s local timezone.

Reports and operations

Community reports are firsthand accounts reviewed by an editor, not instrument measurements. Snow depth, visibility, lift status and piste quality are not inferred from snowfall. For operations, use the official resort report.

Sources

ECCC open weather data · MET Norway weather forecast · OpenSkiData / OpenSkiMap, © OpenStreetMap contributors, Skimap.org, Who’s On First and © Mapterhorn. International lift-terminal locations and elevations are approximate map data, not surveyed resort elevations. Canadian points retain their existing OpenStreetMap and Natural Resources Canada provenance.

Download the resort registry · ODbL 1.0 licence. Forecast values and the resort database have separate source licences.

Landscape photograph: Connor Danylenko / Pexels. Used for atmosphere; it is not a live camera image.