Snow Sports Weather - Module A: case ID = s00

s00: page 3 of 3 - steps 7 to 10

Readings and online activities done by each student individually.

This case was loosely based on an incident in the Rockies in February several years ago (exact date and location are withheld out of courtesy to the victim/family). It was near midday on a warm, sunny afternoon, similar to the conditions you would've experienced in the latter part of the week. No large avalanches had been observed in the past week. The avalanche forecast warned of persistent weak layer buried deep in the snowpack. The danger was rated moderate. It also mentioned that southerly-facing slopes under the warm afternoon sun would be the most suspect, especially in thinner snowpack areas.

The ski party was on a 35° steep slope, similar to the slopes your group was planning to make side trips onto. Two skiers started down the slope when they triggered a large avalanche from a small area of thin snowpack where the slope angle was locally steeper. The slide was 400-m wide, 1000-m long, and 40- to 200-cm deep. One skier was able to escape, skiing off to the side. The other skier was caught and only partially buried. Unfortunately he was killed by trauma during the course of the avalanche.

The initial NWP weather forecast that was available to you was accurate for most of the week. However, a storm did move in on Friday night, continuing into the day Saturday. This wouldn't be an issue had you started on Monday (finishing Friday). If you started a day later on Tuesday, luckily, your party would have already climbed over the Balfour High Col - the most weather-exposed part of the route on Friday. You would have been at the Duncan Hut Friday night, and had a short exit off the glacier on Saturday down below treeline where stormy conditions would be less of an issue.

Related Stories and Links

About 6 or 7 years ago, I was snowboarding in resort at Whistler Blackcomb on a sunny spring day. I was traversing into the Lakeside Bowl on Blackcomb in the early afternoon, and I paused to wait for my friend (who had never done this rocky and somewhat tricky to navigate section before). She caught up, and I heard someone shout after us.
Ski patrol came zooming over following our tracks and told us that we should not be there! Apparently they had just roped off and closed the gate to this terrain after we had gone through. We hadn't done anything wrong, it was just bad timing, and it is a good thing I paused when I did. The reason, as ski patrol explained quickly to us, was that there were (south-facing) cliffs just above us loaded with snow that was warming up in the afternoon sun, and we were at an increasing risk of being caught in an avalanche. If we had continued into the bowl (also south-facing), the risk would have been even greater since we might have actually triggered an avalanche ourselves!
We were able to backtrack slightly and head down a safer part of the ski hill without any issue. It was a good lesson to be more aware of conditions, even when riding in a resort

This is not really a related story, but a compelling 4-part series on avalanches and decision making. For those that are interested, we are posting one part per module.
Part One: Human Factor: Chapter 1

Updated weather forecast and satellite	Weather forecast from Friday morning (26 Feb). Precipitation shown in blues and greens. Link to IR Satellite Loop Infrared satellite loop showing high cloud-tops associated with the precipitation that arrived on Saturday morning in the Wapta traverse area. (Credit: University of Washington, USA.)
Tips from meteorologists	Numerical weather prediction models tend to get less accurate as they go farther into the future. This is important to remember when planning a multiday trip in the alpine (where the risks are higher). Having a way to get weather updates can greatly increase your chances of completing your trip, as it allows you to a) remain safer in bad weather, and b) take better advantage of good weather windows. One way to do this is via a satellite communication device called a Delorme InReach. You can get text weather forecasts for your location, or better yet, do two-way text messaging with a friend that's taken this course and can give you updated weather forecasts. A similar but more expensive option is a satellite phone. A Delorme InReach or satellite phone can be purchased or rented for your trip. As an example, the early arrival of a storm might take you by surprise, pinning you in your tent in an exposed alpine area for a day or more (not all tents can stand up to abuse from strong winds and heavy precipitation and may collapse). Conversely, having an updated forecast may allow you to climb ahead over an exposed pass, confident that you will have a full day of good weather in which to do it before a storm arrives. An expedition team I recently gave forecast support to was able to make it to the summit of Mount Logan (the highest peak in Canada) because they had a recent forecast update about an approaching storm.
Thoughts from avalanche expert Mike Koppang Kananaskis County Public Safety	Even experienced skiers can underestimate the effects of warm temperatures and variability in snow depth and characteristics in the start zone (near the top of a slope that is capable of avalanching). Deep persistent weak layers can lie dormant for weeks or months, but when triggered usually result in large, dangerous avalanches. Avalanche hazard is not limited to those skiing in the start zone. In the real-world case that this module was based off of, a different group at the bottom of the avalanche path very narrowly avoided being hit by the avalanche. When traveling in or below avalanche terrain (slopes steeper than about 28°), always be properly prepared (avalanche gear and training) and pay attention to what is happening on slopes above you.

If you could start over for this particular case study (knowing the actual outcome from Step 7), what would you do differently as a pilot?

For example, would you make a different decision?

Would you want more or different data to help you make your decision (if so, which data), etc.

Enter your statements into the UBC Canvas system, for the module: Snow Sports s00 Step 10.

These count towards your grade (for grade weights, see the Evaluation link from the course home page). The grade is based on the relevance of your statements for the scenario of this learning module, and on the indication that you learned from your mistakes (if any), not on the amount of statements you make. Please be brief/succinct.