Skip to content

Quick tour

The header

The header across the top shows:

  • Snowmapper and the name of the region.
  • Last run: when the board was last rebuilt, in UTC (e.g. Last run: 2026-11-05 07:42 UTC). Hovering over it shows the engine version.
  • Tabs: Map, and depending on the region Warnings, Climatology, Val-Lab, and always Info.

Boards rebuild once a day. If the last run is 36 hours old or more, an amber banner reads "Data may be outdated". It turns red at 72 hours. You can dismiss it with ×, but the numbers stay old.

The tabs

Tab Shows Present when
Map Daily maps of weather, snow, anomalies, satellite snow cover and the forecast always
Warnings Danger levels 1–5 per area per day, with snow line and freezing level warnings are configured for the region
Climatology This season vs past seasons for a basin or catchment a climatology exists
Val-Lab Model vs satellite snow cover and vs station measurements satellite or station data exist
Info Run details, links (including this manual), partners always

Five steps to your first map

  1. Open the Map tab. The date slider at the bottom of the control panel opens on today. The marker on the slider is today.
  2. Choose a layer in one of the dropdowns: e.g. Model → SWE for the water stored in the snowpack, or Model → Snow Depth.
  3. Hover over the map for the value at that place, in the tooltip.
  4. Drag the slider, or press ▶ to animate. Dates after today are forecast.
  5. Click anywhere on the map for a meteogram: the 10-day forecast of temperature, precipitation, snow and wind at that point.

Then try Anomaly (vs climatology) → SWE anomaly: it shows where there is more or less snow than usual for this date. See Anomalies.

What "today" means

The model has two parts in time:

  • Analysis (past to the present): driven by ERA5 reanalysis, the best available estimate of past weather. ERA5 arrives with a lag of a few days; the gap up to today is filled with the most recent forecast.
  • Forecast (today onwards): driven by the latest ECMWF forecast, about 10 days ahead.

The two are blended over a few hours, so there is no jump at the join. See Forecasts.

Units and time

  • Values are in UTC days unless a panel says otherwise. The meteogram converts to local time for the region.
  • SWE is in mm of water (1 mm = 1 kg m⁻²). Snow depth is in cm on maps. Snowfall is in cm of fresh snow. Full list: Variables.