Storm Slabs
- Hochgebirge
- Waldgrenze
- Unterhalb der Waldgrenze
- Wahrscheinlichkeit
- Likely
- Größe
- 1–2
Expect avalanche danger to edge towards the upper end of Considerable as the day progresses. On non wind-affected slopes, storm slabs are likely to avalanche with a human trigger. During the first half of the storm, temperatures are forecasted to increase, meaning we could see a bit of an "upside down" snowpack, leading to more touchy avalanche conditions. Thankfully temperatures will cool as the storm progresses, but don't expect the danger to decrease so quickly. Wind will ramp up and redistribute storm snow in exposed areas into wind slabs, which is where you will probably encounter the largest and most reactive slabs. Expect to find more of this as you gain elevation. During this storm, it's best to play it safe and identify any locations where more than about 6 inches of storm snow exists, and avoid these areas on slopes steeper than 35 degrees.
If we experience periods of intense snowfall, shallow natural avalanches could occur during this time, as the snow struggles to adjust to the rapid change. Natural avalanches are possible with Considerable avalanche danger. Most avalanches will likely fail within the new storm snow, which will grow in size throughout the day. This means you could trigger an avalanche around 6 inches to a foot deep, or possibly deeper as the day continues. However, there are a number of crusts, storm interfaces, and a graupel layer in the top couple feet where there's a small chance a failure could occur on one of those deeper layers. In general, a large variety of surfaces exist beneath the new storm snow layer we'll be getting.
Pay attention to red flags as your strongest indicators to avoid steep slopes. This includes recent avalanches, long shooting cracks, and whumphs. Other red flags include heavy snowfall and strong wind, both of which you'll probably see on Thursday as well. When in doubt, stick to lower-angle slopes as the storm passes through.
Fresh storm slab avalanche crowns on Shuksan Arm near treeline which happened earlier this month. This is similar to what you might see on Thursday.
Photo: Mt Baker Patrol