Estimate avalanche risk from slope angle, recent snowfall, wind loading, weak layers, temperature change, aspect, terrain traps, group size, and the posted avalanche forecast danger rating. This calculator is an educational planning tool for backcountry skiing, snowshoeing, splitboarding, winter hiking, snowmobiling, and mountaineering.
Forecast and terrain:
The calculator starts with the posted avalanche danger rating, then adds risk for slope angle, aspect, terrain traps, and travel plan.
Snowpack clues:
Recent snowfall, wind loading, weak layers, recent avalanches, warming, and warning signs increase the risk score.
Human factors:
Group size, training level, rescue gear, and terrain choice affect the final recommendation because avalanche accidents are often decision-making accidents.
An avalanche risk calculator can help organize observations before a winter trip, compare safer terrain choices, and highlight red flags that should make a group stop or turn around.
This is not a forecast, not a stability test, and not a go/no-go authority. Use your local avalanche center forecast, formal avalanche education, field observations, and conservative terrain choices.
This calculator uses a practical weighted risk score:
Risk Score = forecast danger + slope angle + snowpack red flags + weather loading + terrain consequence + group factors
No. This calculator is only an educational planning aid. It cannot evaluate real snow stability or replace avalanche training, forecasts, or field decisions.
Many slab avalanches release on slopes around 30° to 45°, especially when recent snow, wind loading, or weak layers are present.
Major red flags include recent avalanches, cracking snow, collapsing or whumpfing, rapid warming, heavy new snow, strong wind loading, and rain on snow.
Everyone entering avalanche terrain should carry a working avalanche transceiver, shovel, and probe, and know how to use them through regular practice.