UTAH (ABC4) – The National Weather Service has issued a winter storm warning from Wednesday morning through Saturday, anticipating significant snowfall and strong winds through most of the mountains in northern Utah.
It’s expected the storm will create dangerous avalanche conditions, heavy snowfall will crowd slopes, natural avalanches will occur, and people will be caught in particularly large avalanches if they venture into avalanche terrain.
The snowpack has shown us what will happen when the storm arrives, as there were a number of avalanches and close calls after last weekend’s storm.
According to the Utah Avalanche Center:
- Avalanches may start within new snow layers, but will then break at the ground and produce avalanches that break up to six feet deep and hundreds of feet wide.
- Avalanches are often triggered by people: In 90% of avalanche accidents, the victim or someone with the victim triggers the avalanche in some way. When natural avalanches occur, it is usually because snow is blown over weak layers of snow or rapid warming weakens the layers. In these cases, there are often clear signs that the snow is unstable.
- Avalanches are not usually made up of loose snow: Rather, dangerous avalanches are caused by plates or layers of snow which can weaken and shatter, causing them to slide. Avalanches made up of loose snow (called sluffs) do not often cause deaths or any notable damage.
- Avalanches travel quickly: It can be very difficult to impossible to outrun an avalanche unless you are on a snowmobile. Even then, it’s not always possible. An average avalanche can travel about 80 miles per hour, while a large avalanche can travel faster than 200 miles per hour.
- Avalanche accidents usually happen in the backcountry: Snowmobilers are almost twice as likely to die from an avalanche than from any other snow activity.
- People caught in avalanches don’t die from lack of oxygen: Even dense avalanche debris is usually full of air. Those buried in snow are more likely to die from carbon dioxide poisoning which collects around their mouth.
- For avalanche victims, the first 15 minutes are key: 93% of buried avalanche victims are found alive if they are rescued within the first 15 minutes. After 45 minutes, only 20 to 30 percent are recovered alive.
Anyone heading into the backcountry should check the avalanche forecast each day. If you do choose to go out into avalanche terrain, make sure to check everyone in your group for operational avalanche rescue gear and be sure everyone knows how to use it, cross steep slopes one person at a time and avoid being under any slopes, even small ones.