understanding snowpack & reading avalanche reports
Written by Michael Wachs, AMGA Certified Ski Guide
CONFIDENCE: the feeling of self assurance in our own abilities. Confidence in your choices comes from experience, and backcountry skiing or riding is no different. To gain confidence in reading avalanche reports and relating the information to the current snowpack, you must gain experience over time. I’ll be breaking down the details of how I do this as a professional mountain guide in the Tetons. In this article, we’ll cover: how to read the forecast, take notes of what patterns we see going on and while we’re out on a tour, and how to observe any hazards there might be relating to the forecast and snowpack.
Sometimes, you’ll go out and see a difference between what was listed in the forecast and the actual conditions (ie. more snow, more wind, more avalanche activity). This difference should be considered a warning to your confidence in knowing the conditions for your descent. However, if we read the forecast, identify the hazards while on a tour, and affirm what we have read, that will give us assurance in our forecast.
Consider this example: If the forecast says that the avalanche hazard is considerable with 6-9 inches of new snow with moderate winds from the SW, buried facets could most likely be loaded to cause avalanche activity.
Here are some ways to approach this forecast...
Sometimes, you’ll go out and see a difference between what was listed in the forecast and the actual conditions (ie. more snow, more wind, more avalanche activity). This difference should be considered a warning to your confidence in knowing the conditions for your descent. However, if we read the forecast, identify the hazards while on a tour, and affirm what we have read, that will give us assurance in our forecast.
Consider this example: If the forecast says that the avalanche hazard is considerable with 6-9 inches of new snow with moderate winds from the SW, buried facets could most likely be loaded to cause avalanche activity.
Here are some ways to approach this forecast...
Reading Wind
Choose a tour that will give opportunities to observe those concerns. With the winds, you want to be on a ridge or able to observe one to see if: a) the winds are strong enough to load leeward slopes, or b) the winds are coming from the direction forecasted.
Identifying Facets
Find a location on the tour to dig and see if you can identify facets within the snowpack. If those observations are different from that forecast, such as the winds are stronger, there is much more new snow than predicted, or there are facets in the snowpack where you didn’t anticipate, this should make you lose confidence and take a safer path avoiding those characteristics in avalanche terrain.
Digging Snow Pits
Digging snow pits is another way to access and evaluate the integrity of the conditions. However, simply digging one snow pit isn’t the answer to a full perspective of the conditions, as it gives you a very detailed description of only the 30cm block and its surroundings. The higher the number of small, quick pits you can dig, the more information you’ll have to make informed decisions.
Quick Pole Checks
Using the handle of your ski pole to find lighter snow under heavier snow is an easy method you can do many times on a tour to find the simple recipe for an avalanche in the snowpack: heavy over light, strong over weak.
