Winds that gusted to near 100 mph in the Kenai Mountains south of Anchorage on Thursday had died down by this morning and heavy snows were easing, but the Chugach National Forest Avalanche Information Center continued to warn people of how quickly and easily the Alaska mountains can kill.
Extreme avalanche conditions in the Turnagain Pass area on Friday caused many natural avalanches that helped to make conditions safer in some places in the popular recreation area east of the state’s largest city, but the area remains far from safe.
“A combination of several feet of new snow, powder starved people and clearing skies this weekend all equal a chance for an avalanche incident,” the center warned in its morning forecast. “Between two to four feet of new snow fell over the region Thursday night through yesterday morning.
“Many natural avalanches were seen, yet at the same time, many popular areas were obscured in clouds and little information exists. Therefore, we know the new snow that rapidly loaded slopes avalanched immediately in some areas, but we are suspect that more slopes remain intact and could be lying in wait for a human to tip the balance. How quickly the storm snow will bond to the old surface is uncertain and today (and tomorrow) are days to let the slopes adjust.”
The National Weather Service had posted an avalanche bulletin at the Center’s request warning of danger in the mountains from Girdwood all the way to Seward on the shores of Resurrection Bay. The Seward Highway, which runs through the heart of the area, remained open. The Alaska Department of Transportation reported slippery driving conditions, but had posted no warnings of temporary road closures due to avalanche control, a normal activity along the 100-mile road in weather like this.
How seriously Alaskans heed the warning remains to be seen.
A popular recreation area for snowmachine riders, backcountry skiers and snowboarders, Turnagain is a powerful draw for some even if it is now a potential death zone thanks to up to the waist-deep new snow and winds that peaked at 96 mph. The winds moved a lot of snow around at high elevations to windload ridges and the windward side of gullies.
The center did think the snowpack has stabilized enough that it is now safe for snowmachiners and fat bikers to ride in the valleys of the Portage, Placer and Twentymile rivers. Conditions were so touchy Friday the Center was warning people to avoid even those lowland areas.
“Avoiding avalanche terrain is necessary today, which includes staying far away from runout zones of larger slopes above,” the center warned on its website. “An avalanche from above could run into valley bottoms, especially in places like Seattle Ridge, Portage Lake and Placer Valley.”
It is not often the center warns of avalanche dangers near sea level in the Placer Valley or at Portage Lake, but conditions were extreme.
The explosive danger was and remains the possibility natural or human-triggered avalanches in the all the new snow could “‘step down’ into a deeper weak layer causing a very large avalanche to send debris well into valley bottoms,” as the Center report Friday
“Several widespread persistent weak layers exist within our snowpack region wide including buried surface hoar and facets one to two feet below the old surface. Don’t forget we haven’t had a storm like this in months. Lots of uncertainty exists around how our old weak snowpack will adjust to its new load.“
Turnagain Pass is the site of the worst recreational avalanche accident in Alaska history. In March of 1999, an avalanche of the sort now being described possible broke a half-mile wide and seven-feet deep high on a southeast facing slope above the Seward Highway.
Dozens of snowmachine riders were in the area when the side of the ridge above a big, Turngain parking lot ripped out. One of them was thought to have triggered the slide. Many were able to power away from the runout zone as the avalanche thundered toward the valley, but at least 10 people were caught in the slide.
For days, as rescuers tried to track down people who’d been in the area when the snowslide hit, there were concerns the death count might go as high as nine.
Luckily, some of the missing were later discovered to have left the area and were safe, but six people were confirmed dead. It was a massive tragedy.
The avalanche conditions then were similar to those being described by the forecast center now.
The Alyeska Resort in Girdwood, just south of Turnagain Pass, was reporting great powder skiing in 42 inches of new snow Saturday morning. The resort conducts extensive avalanche control. It looked to be the only truly safe place to ski south of Anchorage for those looking to venture onto slopes steeper than 25 degrees, which is where avalanche dangers really begin to ramp up.
And even in the latter areas, there are at the moment very real dangers from what could come down from higher above. Two snowshoers were killed in the Eagle River, a suburb just north of Anchorage, in 2002 when a snowfield high above them avalanched and funneled down into the gully in which they were hiking.