Snowpack, slope and signal

01Field scene

A valley in alpine terrain.

A private cell on the valley floor, a weather station on a shoulder, a compact radar and a seismic vault stand on terrain drawn from a real elevation model. The red stipple is the ground the mast can see; everything in shadow needs a relay or a different site.

Figure as text: Stations and coverage in an alpine valley

An alpine valley from elevation data: a cell tower on the floor with its visible ground in red stipple, a weather station, a compact radar on a ridge and a seismic vault.

• Cell site
• Weather and snow
• Compact radar
• Seismic vault

02Layer stack

Reading the terrain in layers.

Forecasters judge avalanche problems on terrain: slope, aspect, elevation band and exposure to wind¹. A layer stack makes those inputs explicit: contours, the stations, the access routes, and a modelled slope class whose red line marks the steepest ground.

Figure as text: Avalanche terrain as registered layers

An exploded stack: terrain contours, imagery, land cover, routes and structures, stations, an analysis grid and a modelled terrain class with a red threshold line.

1. Terrain: Contours from the elevation model.
2. Imagery: Optical and radar scenes.
3. Land cover: Forest, open slopes and rock.
4. Routes and structures: Roads, rail and buildings exposed to avalanche paths.
5. Stations: Weather and snow stations; red ones are reporting now.
6. Terrain class: A modelled slope class; the red line marks the steepest ground.

03Simulator

A station that must last the winter.

In a narrow valley in December, the sun clears the ridge for only a few hours. A snow station’s battery has to carry it through storms that bury the panel. Set a short winter day and a heavy load to see the margin.

Figure as text: Winter energy balance of a remote snow station

A line chart of stored energy over fourteen days with a dashed reserve line.

04Systems diagram

The scale the public reads.

Behind every public bulletin is a danger rating on a five-level scale used across North America, and a description of the avalanche problem². Better observation does not change the scale; it narrows the uncertainty behind each rating.

Figure as text: From stations to the public bulletin

A four-tier diagram: stations and field reports, radio relays, the forecasting office, and the public bulletin and transport operators.

• Observations: Snow station, Ridge wind, Field reports
• Relays: Relay, Satellite
• Forecasting: Forecast office
• Bulletin: Public bulletin, Road and rail

8 links. Scenarios: Normal operation; Relay buried.