Winter wonderland can be dangerous

Winter sports enthusiasts greeted this winter’s early snowfalls with wild anticipation. After several years of a low snow pack, this winter looks promising for snowmobilers, snowshoe travelers, and both alpine and Nordic skiers in the backcountry.

In the Sisters area, skiers, snowshoers and snowmobilers have been out enjoying winter recreation from the Santiam Pass south to the slopes of the Three Sisters and Broken Top.

But conditions can change fast, bringing danger to winter recreationists. One of the most serious risks is avalanche.

After an above average snowfall in late November and early December, the Central Oregon Cascades experienced a combination of higher than normal temperatures and rain followed by periods of more snow and low temperatures. This weather pattern has repeated several times, setting the stage for avalanches. In recent weeks, warnings have been issued alerting local backcountry travelers to the potential hazards they may face.

Avalanche hazard experts say there are four factors that can cause an avalanche. There first must be a layer of new snow known as a slab. This slab is covered by a settled section of dense snowpack called a bed surface.

If this snow condition occurs on a steep slope that is on a 30-degree angle or greater, the third factor is in place. Most avalanches occur on slopes of 38 percent or more.

The last condition is something that triggers the avalanche based on the amount of weight that the snow can hold. This triggering action can be caused by activity of a person in a snowmobile, on skis, or just walking, by an animal, or just by the weight of one more snowflake.

The type of snow created by the shape of the snowflake can determine how stable a snowpack is. We have always heard that no two snowflakes are alike. In the same way, there are many different types of snow. Snow shaped in crystals creates the most stable snow because the six points of the flakes interlock with others. When snow in the form of granules or pellets accumulates the granules roll over one another, creating loose and unstable snow. This type of snow is the most likely to be involved with avalanches. A layer of this loose snow can slide over a base of solid, stable snow.

One other hazardous type of snow condition is a layer of snow known as a snow hoar or “sugar snow.” With this condition, snow crystals are large, round, and cup-shaped. These crystals act as ball bearings, causing any snow on top to slide off.

As heavy winter rains move up in elevation into mountain snowfields, the weight of the snow increases, bringing with it the risk of avalanches.

For any winter backcountry traveler, avoiding an avalanche is the best option. Keep informed of snow and weather conditions, talk to other winter travelers and watch for signs of environmental conditions that indicate a dangerous situation.

The next step is to go prepared. Don’t travel the backcountry alone and always let someone back home know your travel plans. Besides the usual survival gear, carry an equipment pole, an avalanche beacon and a shovel. Practice using these tools so you know how to search for someone.

Don’t try to go for help; immeditate action is needed.

Rescue teams usually will take an hour or more to reach you. An avalanche victim has only a 50 percent chance of survival if buried for more than 30 minutes. In fact, the first 15 minutes are most critical in the rescue of a victim.

By keeping informed and going into the backcountry prepared, you can enjoy the beauty and solitude of a winter wonderland and live to enjoy it another day.