Avalanche conditions update 2-18-10:

Overnight, the surface snow around upper Hatcher Pass has turned wet and heavy---the layers underneath are still unconsolidated which means the heavy stuff can slide on it. This heavy, wet snow is the kind that rips trees and Humans apart and entombs the remains with instant solidification.

This blog column is intended to be obvious. When avalanche conditions exist in the mountains in one part of South Central Alaska there is a good chance they will exist in most other mountains in South Central. It may be obvious to some but apparently not to those unfortunates who get caught in avalanches---which is why I write this stuff. - R.W.

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It was at least 25 years ago. I was living in Anchorage and driving South on the Seward Highway for a day of climbing in the Chugach Mountains along Turnagain Arm.

As I rounded the bend near Potters Marsh a burst of warm, wet air came rushing into the car window. It was so dramatic that I immediately turned around and decided to climb elsewhere that day.

Unfortunately, a group of skiers had apparently decided to trek into the mountains on that very same day. I tried to Google the particulars for this column but couldn’t find the reference (I’ll bet someone out there can tell us). As best I recall, four people died in an avalanche at a place called Mt. Ptarmigan and one person barely made it out wearing minimal clothing---a T-shirt as I recall. It had been so warm that the party had removed clothing and they were not wearing full gear when the avalanche hit. I believe the survivor had lost his skis and struggled hard to get back in very deep snow.

The survivor said the group had initially encountered that type of snow which goes “Whump” and collapses when disturbed---even on level ground. Yet, the group had decided to go on into the mountains anyway. With terrible and fatal results.

For me, it is sometimes safer to travel alone---there is no one to challenge me into unnecessarily risking my life in order to stay with the group. But that’s just a sidebar.

The technical means to analyze snow pack conditions and slope angles are well-known and publicized. Cutting a cross-section of snow to examine the various layers and how they are, or are not, being held together and supported, is most instructive. Of course, few people bother with this.

There is also something to be said for observing the snow and the weather on a day-to-day basis. Few people have the opportunity to do this.

Aside from being constantly outdoors, nearly every day of the Winter I gather up snow to melt on the wood stove for the dogs, for cooking, for drinking and for washing. This gives an intimate, daily insight into snow conditions in the nearby Talkeetna Mountains as well. And, by watching the weather reports and reading the newspaper, I can apply observations of local snow conditions over a much larger area.

I was saddened by that tragedy along the Turnagain Arm simply because I mourn all those lost in the mountains. I was particularly saddened because of knowledge I had that I could not share with this particular group. And it happens to me just about every year. I will “feel” the avalanche conditions and tell a few friends.

“Where will the avalanches happen?” they will ask me.

“In the mountains,” I will reply. And, sure enough, a snow machine trailbreaker for the Iditarod will be killed by an avalanche.

Sometimes I don’t get a chance to tell anyone. I’m alone, outside my cabin, gathering the snow and feeling the warm, moist air. Next day I will read about someone dying in an avalanche right here in these Talkeetna Mountains. All I can do is empathize.

Snow conditions are never exactly the same in different Winters. Locally, we have had a decent amount of snow. Like last year, the snow has been powdery, dry and it has been cold enough to keep the snow underneath from consolidating. This means that the snow is loose---right down to the frozen ground. It means that making trails might take several passes---with skis, snowmobiles or snowshoes---for the snow to harden into a good trail. It also means avalanche danger over a large area.

While individual areas may have different temperatures at various times, the general trend of a Winter could well produce dangerous conditions over wide areas.

Each Winter the same things happen, I go outside with my 5 gallon pail and feel my feet sink deep into the snow. I reach down to gather the snow and must compress it into the pail. Sometimes the full pail is extremely light in weight---this tells me the obvious: that the snow is extremely fluffy. Difficult to consolidate but light in weight. Sometimes the snow is difficult to consolidate but the pail is very heavy. This tells me that snow is loose but very heavy. It doesn’t take much to imagine how these different types of snow will react when pouring down a mountain slope.

Large amounts of the fluffy snow would not be any fun in an avalanche. The unconsolidated, but very heavy snow, however, would hit like a ton bricks and probably “set up” like cement under it’s own weight. Add some warm moist conditions and some wind and the danger of avalanche is imminent.

Conclusion: The underlying layer of snow in my area and in the mountains generally is loose and unconsolidated. It also feels pretty heavy. This means that any further snowfall on top of existing snow could prove to be quite unstable.

Now come more real warning signs. Warm weather. Warm moist air. Heavy winds. We just had some heavy winds this morning, on Monday, February 15, 2010. It is warm now (around 30 degrees Fahrenheit); has been warm for days; and is forecast to remain warm and perhaps even rainy for days.

Okay, at least one and most likely two people just died after getting caught in an avalanche on Spencer Glacier. A skier also died in the Chugach Mountains after triggering an avalanche.

Here is my heartfelt warning: Anyone considering entering the Talkeetna Mountains---or any mountains in South Central Alaska right now---should exercise extreme caution. The State Park has issued an avalanche warning for the Hatcher Pass area.

What this means to me is to stay far away from underneath any type of overhanging snow pack---even on opposite, reverse slopes. And also to stay well away and off the tops of snow cornices that stick out from ridge tops. When these cornices let loose they drop suddenly and quickly, like one of those trap doors in a cartoon. I’ve stood on rock ledges right next to these things---when they let loose the bottom drops out and the ground shakes.

Sometimes avalanches begin with a little trickle…they may even stop. But once things get going they move like crazy. My general rule of avalanche safety is to stay out of the mountains when all the warning signs are there. These conditions occur just about every year at some point. And right now all the signs are there.

THAT WARM MOIST FEELING -

Warm, moist air is the single most important avalanche warning for me. Warm, moist air enters the spaces in the snow pack and lubricates everything. I think it also adds weight to the snow pack. Whenever I hear about people getting caught in avalanches it always follows periods of warm, moist air conditions.

After a few weeks of warm weather---and with the return of colder temperatures---the moistened snow will freeze and consolidate and you can climb, ski, snowshoe or high-mark to your heart’s content. That’s assuming that the consolidation has been complete---from the top of the snow pack to the bottom.

Since I travel mostly alone I carry no locator beacons or avalanche probes. Of course I am taking a chance---that’s why I am otherwise super-cautious.

Some mountaineers get a false sense of security traveling in groups with avalanche safety equipment---but that’s assuming they don’t get killed by the avalanche. Some Alaska skiers, boarders and riders think they can "outrun" avalanches. Others simply love to risk their lives---which is their thing. Still, I don't think most people want to get themselves killed.

I would suggest walking around in the snow to let your feet feel what conditions are at different levels. Kick the snow. See how deep you can stomp your way toward the bottom. Stick your ski poles into it to see how hard or soft it is. Look at the snow. Feel the snow. Feel the moisture in the air. Observe the weather and the wind. Study the darned snow before you start traveling on it. Figure out what the weather conditions might be doing to the snow before you risk your life.

There’s a lot more to avalanche safety than this brief, hurriedly-prepared segment. There are courses of study about avalanche safety and preparedness. So, pay attention and don't get cocky in the mountains. And, I do believe, when the air is warm and moist the danger of avalanche is most extreme.

Rudy Wittshirk