It's simple enough. Just like walking . . . one foot in front of the next, arms swinging and head up. Which is part of the appeal of cross country skiing - it's as easy as walking.

It's also seasonal. It takes snow to ski. The sport's main element, however, is also brings its most common enemy - avalanches.Combine the two and you get an easy sport that needs to be approached with some caution.

Frequent snow storms this year have led to some good skiing, but also made it imperative that skiers be aware of snow conditions.

The best source is the Utah Avalanche Forecast Center. Twice daily the recorded message is updated with the current snow conditions in the backcountry.

Dave Hanscom, with the Utah Nordic Alliance, recommends skiers call in regularly, "just to monitor the snow. If I know I'm going out, I start calling two to three days before. You need to know what's happening with the snow pack several days before, not just the day you go out.

"A lot can happen in a few days. Get a small storm and you may think everything is all right. But a wind will deposit the snow in certain areas, sometimes in substantial amounts. I learned the hard way. We went out the day after we had a light snow and wind and thought everything was all right. We got caught in an avalanche and one skier was completely covered. Luckily everything turned out OK."

According to Bruce Tremper, director of the avalanche center, understanding avalanche danger is based on looking for and understanding patterns.

"What we do at the center is let you know the basic setup (of snow conditions), then it's up to you to do the interpretation.

"For example, we tell you the underlying snow is stable, but that winds have blown snow into pockets. Or, to stay off all north-facing slopes. Or, in the spring, to stay off south-facing slopes," he said, "then it's up to you to interpret the information and ski where it's safe."

North-facing slopes are typically the most prone to avalanches because they get less sun and temperatures are colder, which causes weak layers to develop. In the spring, the sun warms up the south-facing slopes, which makes them more likely to slide.

The most dangerous avalanches are the slab slides that occur during the colder months.

Tremper explained that with these slides, "a skier typically will get out in the middle and then it will break lose, usually somewhere up above the person."

Another dangerous condition is called "depth hoar," or "sugar snow." This is a metamorphosis that happens in the snowpack that creates a weak layer of granular snow.To determine this conditions, a skier must dig a snow pit and actually view the different layers. Experts at the center are doing this three to four times a week in different areas.

Tremper went on to offer these suggestions to those skiers heading for the backcountry:

- First, contact the avalanche center for a snow report. He also recommends calling days ahead of a planned outing to help determine the pattern.

- One of the most common signs, and one frequently ignored, is to look for recent avalanches in the area. If the snow slides once, it may go again.

- If the snow collapses underfoot, then that too is a good indication of instability in the snowpack.

- Watch for cracking or fracturing. The longer the crack, the more hazardous the snow.

- Look for signs of added weight on the snowpack, such as added snow from a recent storm or snow that has been pushed into an area by the wind.

- We aware of the winds. The wind is the most important factor in avalanche formations. Winds can transport a tremendous amount of snow in a short time.

- Be especially cautious of avalanche problems the day after a storm. This is usually when the snow is the most unstable, before it has had a chance to bond to the old layer.

- Take an in-depth avalanche class. As long as skiers are aware of snow conditions and know what to watch for, they can go cross skiing in the backcountry anytime.

Avalanche forecast

Backcountry enthusiasts are urged to check on snow conditions before planning trips or leaving home. For updates, call 364-1581.