Avalanche
Slope, aspect and bulletin on one offline map. The route line is checked against the shaded band, not against memory.
Activities · Snow · Skill 3–5 · High to extreme risk
Slope angle. Aspect. Bulletin. Read all three.
Avalanche terrain is the one hazard in the app where the data is genuinely decisive and genuinely available. Slope angle from LiDAR, aspect from the DEM, and the regional bulletin — on one map, offline, at the trailhead where the decision is actually made.
01 / By the numbers
30–45°Critical slope bandShaded directly on the map
4Layers auto-enabledSlope, avalanche terrain, weather, huts
1mLiDAR resolutionWhere USGS 3DEP coverage exists
0Signal needed at the trailheadThe bulletin syncs before you leave the road
02 / What the app enables
Pick the activity. The map configures itself.
These layers switch on together, because they are the set this activity actually needs. You can change any of them; the point is that the default is not a blank topo map.
- Slope angle
- Derived from the highest-resolution DEM available, with the critical band shaded.
- Aspect
- Because the same angle behaves differently facing north.
- Avalanche terrain
- Classification, plus the regional bulletin where one is published.
- Winter weather
- New snow, wind loading and the freezing level.
- Huts and refuges
- Capacity, season and access.
03 / Failure modes
The ways this actually goes wrong.
Every activity in NavTrax carries a documented failure-mode list, and each entry names the feature that addresses it. Not a disclaimer — a design input.
Whiteout navigation error
Offline region with contours, plus dead-reckoning fallback when GPS degrades under heavy cloud and terrain.
Terrain trap
Slope and aspect derivatives make gullies and convexities visible on the plan, before the skin track commits to them.
Hypothermia
Health telemetry with skin temperature, against the member’s own baseline.
Partner separation
Mesh keeps the party linked in a drainage with no cellular, and the leader dashboard shows who is where.
04 / Practice
What the app assumes you already do.
- Bulletin before the road ends
- Synced automatically while you still have a signal.
- Slope-angle discipline
- Shaded on the map, not estimated by eye.
- Companion rescue practice
- Not an app feature. Do it anyway.
- Conservative aspect choice
- Aspect layer makes the choice explicit.
05 / Curated kit
The gear list, scoped to this activity.
Pulled from the activity's own equipment profile and matched against the in-app store catalog. Nothing here is a generic recommendation.
SafetyTransceiver, probe, shovelChecked at the trailhead
SafetyAirbag packTerrain-dependent
SkisTouring setup with skinsTech bindings
WarmthLayers plus a belay parkaFor a long transition
NavigationPhone with offline regionPlus a compass
CommsMesh nodeDrainages kill cellular
RepairSki straps and a multi-toolBinding failure is common
WarmthInsulated flaskHydration in the cold
06 / Under the hood
How the bulletin gets onto your phone
Decide at the trailhead, with the data.
Slope, aspect and avalanche layers are on Pro, and they work with the radio off.