How to read an avalanche forecast before you leave the resort

An avalanche forecast rates the danger in a mountain zone on a five-level scale (Low, Moderate, Considerable, High and Extreme) and explains which avalanche problems are present, on which slopes and at which elevations. Read the danger for the elevation you plan to ride, then the problems, then the bottom line. A forecast describes backcountry terrain across a whole zone. It is not a judgment about one slope, and it does not replace avalanche training, equipment or a partner.

Avalanche center forecasts are written for terrain outside ski area boundaries. Inside the boundaries, ski patrol manages avalanche hazard on open terrain. If you leave the resort through a gate or skin up from a trailhead, you are in the terrain the forecast describes.

The five danger levels

Level	Danger	In plain terms
1	Low	Generally safe conditions. Watch for unstable snow on isolated terrain features.
2	Moderate	Heightened conditions on specific terrain features. Evaluate snow and terrain carefully.
3	Considerable	Dangerous conditions. Careful snowpack evaluation and cautious route-finding are essential.
4	High	Very dangerous conditions. Travel in avalanche terrain is not recommended.
5	Extreme	Avoid all avalanche terrain. Natural avalanches are certain and human-triggered ones very likely.

Many avalanche accidents happen at Considerable and Moderate, not just at the top of the scale, because those are the days people feel confident enough to ride steep terrain.

Read it in this order

1. Check the date and time. A forecast is valid for a stated period. Make sure you are reading today's, not yesterday's.
2. Find your zone. Forecast zones cover large areas. Confirm the zone that contains where you plan to go, especially near a boundary between zones.
3. Read the danger by elevation. Most forecasts give separate ratings below treeline, near treeline and above treeline. The rating for the elevation you will actually be in is the one that matters.
4. Read the avalanche problems. Each problem, such as wind slab, storm slab, persistent slab or wet snow, comes with the slopes it affects (aspect and elevation), how likely an avalanche is and how big it could be.
5. Read the bottom line and the discussion. The forecaster's summary explains what changed, what to avoid and why.
6. Look at recent observations. Recent avalanches, cracking and collapsing are direct evidence of instability.

What the SkiBuds app shows

The SkiBuds app shows the official zone rating published by an avalanche center, drawn from the public avalanche forecast map layer at Avalanche.org. Before showing a rating it checks that:

• the bulletin is currently valid, neither expired nor not yet in effect;
• the resort's reference point falls inside the forecast zone, and is not sitting on a boundary between zones; and
• the published rating is consistent and can be verified.

If any check fails, the app shows no rating and says why, for example that the source is marked off season or the stored bulletin has expired. Every card links to the full bulletin from the avalanche center, and the card says plainly that it is a zone summary, not a resort or route safety assessment. For resorts in Australia and New Zealand, the app points to local sources instead.

The zone rating is a starting point. The elevation bands, avalanche problems and terrain advice are only in the full bulletin, so read it before you go.

Before you go into avalanche terrain

• Get trained. Take a recognized avalanche course before riding uncontrolled terrain.
• Carry rescue gear and know how to use it: a transceiver, shovel and probe for everyone, and practice with them.
• Never go alone. Ride one at a time on exposed slopes and keep each other in sight. How to find a backcountry ski partner covers where to find one and what to ask.
• Make a plan that fits the forecast, and agree in advance on what would make you turn around.

In the United States, find your local avalanche center through Avalanche.org. In Canada, Avalanche Canada publishes forecasts.

Safety on SkiBuds and on the mountain covers the rest of a safe day out, Chinook winds and snow explains how rapid warming changes the snowpack, and why snow forecasts disagree helps you judge the weather forecast that sits behind an avalanche bulletin. The SkiBuds app is being rebuilt for iOS and Android and is coming soon.