The layered snow surrounding the driveway/Craig Medred photo

A thousand feet above Alaska’s largest city, the winds were Wednesday night building toward hurricane force for the second time in 48 hours.

The National Weather Service was forecasting overnight gusts to 85 mph,  stage 12 on the Beaufort scale which warns mariners of seas “completely white with driving spray.”

The Chugach Mountains above Anchorage, along with the  Kenai Mountains to the south, were white instead with blowing snow as the winds scoured mountain slopes and drove the several inches that had fallen during the lull after Tuesday’s big blow when the gusts at Arctic Valley north of the city peaked at 96 mph.

“The avalanche danger is HIGH for a second day in a row due to heavy snowfall and strong winds in the mountains surrounding Turnagain Pass, Girdwood Valley, Portage Valley, and areas on the Kenai including Summit Lake and the Seward/Lost Lake zone,” warned the Chugach National Forest Avalanche Information Center.

“High avalanche danger extends north from our forecast area including Chugach State Park to Hatcher Pass, where an avalanche warning is in effect until 12 pm today.

Dangerland

Before the winds began, Lars the Labrador retriever led me on a snowshoe in the Chugach foothills. Feeling his way with his feet, he followed old trails buried beneath the windblown snow left from Tuesday.

The weight of the two of us plus the new snow was in places enough to cause the snowpack to settle with an audible “whump.” Lars jumped every time. We avoided slopes over 10 or 15 degrees and stayed away from a couple avalanche runouts that can move snow a long way downslope in conditions like this.

The danger was there in levels like a layer cake. A cake like that came apart near Boulder Creek on the Kenai Peninsula a week ago and killed 32-year-old Kekai Dang of Kasilof. About a week before that, another layer broke at Anchorage’s Kincaid Park in Anchorage and caught a group of Junior Nordic skiers. 

Several were caught and one was fully buried, but thankfully was dug out alive. No one was seriously injured. It was luck.

Kincaid slabs/Facebook

Bad and badder

All of those layers are still there. The snowpack could come apart at several levels even on shallow slopes. The Avalanche Center was warning people of slopes greater than 30 degrees.

Who reading this can recognize a 30-degree slope? The staircase in a modern house is usually about 38 degrees, a prime avalanche angle. But transposing that visual onto a mountainside is not that easy.

Ski slopes might be a better guide. The “blue” runs – a step up from the easy “green” runs – are 14 to 22 degrees at most U.S. ski resorts. Slope angles are important.

As the Kincaid slide illustrated, some of the predictably most dangerous slopes are not obvious to everyone. The lack of knowledge has proven deadly in the past.

A 33-year-old doctor in training, Angela Paez from Seattle, died in an avalanche at Crow Pass near Girdwood – a ski-resort community southeast of Anchorage – in a year like this when the windblown mountains looked short on snow. There was sadly just enough blown into a gully to kill her after she triggered an avalanche while cross-country skiing.

A companion on the outing with her might have been able to dig her out and save her life, but he lacked a shovel.

Two snowhoers in Eagle River, a bedroom community north of Anchorage, died hiking in what they thought was a safe area in 2002. Unfortunately, they were in a runout area below 4,271-foot Mount Magnificent.

When it let go high above, they were doomed.

The slopes around Flattop Mountain, a Front Range landmark above Anchorage, have been especially deadly over the years. The area in and around Flattop is a magnet for hikers, fat-tired cyclists, skiers and snowshoers.

The snowpack there is now wind-loaded.  The snowpack in places looks especially dangerous.

Beneath all the layers, which tend to break up into dangerous blocks, there is a ground-level layer of loose snow that is more air than ice crystals.

Alaska’s worst avalanche accident in modern history broke to ground level in conditions like this. The year was 1999 and six snowmachine riders died in an avalanche at Turnagain Pass, a popular recreation area along the Seward Highway south of Anchorage.

Be careful ou there.