Alaska Avalanche Specialists/Alaska Windjammer Kites

Sunday, June 14, 2026

Skagway White Pass Avalanche Field Report

Today’s Observations:

I needed to do a visual check on the South Glacier Mountain high starting zones today; almost got shut down by fog, but it parted just in time to get a good look.

It’s obvious that the lower and mid-elevation slopes are melted, settled, and slid out now, with bare ground on the moraine at the right, and with many dirty wet slides onto the lower apron, with no long runouts or entrainment of additional debris. The west bowl has cleaned out well.

The upper east bowl has not all slid out, but close inspection of a zoomed-in detail, after enhancing the contrast, shows well-developed debris channels down the center of every gully, dirty debris off every face, all with short runouts and no sign of secondary slides.

The snow texture is that of summer snowpack now, dirty and stippled with suncups. We have transitioned slowly to early summer conditions without any large slides from the east bowl. The most likely explanation is that the mid-January avalanche cycle cleaned out the early season instability, and then the unusually persistent northerlies scoured these higher north-facing slopes, keeping weak layers from forming on them.

This starting zone is always our last concern as we go into summer. With it now stabilized, we can wrap up the avalanche program for the season. I’ll put out a final forecast to finish it off tomorrow morning.

Outlook:

As always, it has been great working with the railroad and highway crews; our programs are a joint effort that depends heavily on observations and input from the crews. Thanks, and happy summer!

Take care, ride hard, die old!

Shgagwei, Lkoot Kwáan, Lingít Aaní.

We blasted South Glacier Mountain today. Temperatures warmed sharply, reaching 19°C in town and 13°C at Glacier, and the snow softened to the ridges, but we did not get widely-propagating slabs, nor were they triggering secondary slides, or entraining much material. Most slides were relatively small, and none came anywhere near the rails. We had our best results below 1500m, and noted stepped fractures there due to the multiple weak layers formed by our crazy winter weather this year. We jumped on the weather window because it looks showery for a while, and we should be good until the next major warmup now. Shgagwei, Lkoot Kw'aan, Lingít Aaní.

Rime feathers some 10-30 cm long and 5 cm high grow on the snow surface on a 1500m ridgetop on the pass this week. RIme forms from "supercooled" water droplets in the air. Water needs a nucleus to crystallize on, so it can stay liquid even though it is below freezing, if it is in clean, dust-free air, like our coastal air. It freezes on the first thing it hits, whether that's a dust particle, a snowflake, a tree, a rock, or the ground. The feathers grow into he wind, toward the top right of this photo.

As the springtime temperature fluctuates around the freezing point, some of the rime forms in that slushy temperature range between solid and liquid. So the snow surface in the photo also has a thin icy rime crust that was semi-liquid as it formed, allowing it to flow out like latex house paint, freezing into a thin icy crust in the cooler nights. I call this stuff "slush rime"; a phenomenon not well-documented, because it forms under miserably wet and cold conditions when most snow scientists do not want to be out in the field!

Shgagwei, Lkoot Kw'aan, L:ingít Aaní.

Made it up for an on-snow field day on the pass yesterday, even though it did not clear or thaw all that much. It was 7°C, scattered, and slushy when I left the railroad, then intermittent snow showers from 1200m on up, It was only 1°C on the summit, mostly cloudy, with a steady 4-8 m/s south breeze. In my snowpit at 1400m on a 42° NW aspect slope, the thaw depth was 90 cm, down 40 cm from the 50 cm I found three days earlier. Snow temperature at pit bottom was still -2°C in dry windslab.

The crust was hard but breakable rime over moist new snow above 1300m, and did not soften for the descent- very grabby crust! Below there, it smoothed out into soft spring corn snow, starting to rot out near rocks and trees below 1200m. Though I could easily trigger wet sloughs in the slush on the lower slopes, none were releasing on their own.

On the railroad, we are down to only one bit of hanging water ice, just north of Slippery Rock. The 13.8 Mile glide zone is still all water ice, thinning in place, with no sign of movement, and our current plan for the next round of blasting on South Glacier Mountain is late next week.

Conditions are variable, sometimes challenging, but there are some good runs still for backcountry travelers. Beware of changing conditions and rapid thaws. Shgagwei, Lkoot Kw'aan, Lingít Aaní.

Wednesday, May 13, 2026
Report on May 12 fieldwork

Skagway White Pass Avalanche Field Report

Today’s Observations:

We have had a cool but still-thawing 9 days since our last blasting mission. We also had heavy rain to the pass on Saturday the 9th, the heaviest precipitation, and one of only two really wet storms, since mid-January. The snowpack at low and mid-elevations, up to some 1100m, has thawed, settled, and developed drainage capability that makes it a much more stable early summer snowpack.

Other than small sloughs, activity has quieted on the slopes near the pass, along the highway, and even on the 15s on the railroad. Temperatures yesterday were +7°C at our 1400m snowpit, +2°C on the 1530m summit, with broken skies, dry, 10 cm of recent moist new snow above 1250m, and wind S3-6m/s.

Here’s a status report on the avalanche zones:

The 13.8 Mile glide zone is melted down to water ice on rock. We have not seen so much ice before, so are monitoring to see what it will do. It may slide, or it may melt in place. It shows no cracking yet.

The Glacier Glides have melted so rapidly this year that they are largely bare already, with only small slides still possible from them.

There is still one chunk of hanging water ice on the 15.2 Mile path. We have dug a catchment ditch and wall below it, but ice boulders could still bounce over it, so caution is in order.

Slippery Rock had one last chunk of ice hanging on it when this morning photo was taken, but it dropped off later in the day, and was small enough to be easily cleared.

The high, north-facing starting zones on South Glacier Mountain are still not thawed enough to release their spring wet slab avalanche cycles.

We monitor the high starting zones by climbing up into a safer area of comparable elevation and aspect, where we track the depth of thaw. When the thaw reaches the sugary, weak depth hoar layers at the base of the snowpack, it is time for the next round of blasting. Yesterday’s fieldwork was primarily aimed at starting that monitoring.

We dug a study pit on a 1400m NW aspect 40° slope. The top 10 cm was moist new snow from the weekend, topped with a little rime, and underlain by a thin thaw and rime crust. Beneath that is 30 cm of one finger moist melt forms and a 5 cm layer of four-finger moist melt forms, to the lower limit of thaw, still only 50 cm deep. Below that was mostly pencil hard dry windslab to the bottom of the pit at 150 cm, where the snow was just reaching -2°C.

This snowpack is obviously warming, but still relatively cold and dry on the north-facing slopes at mid to high elevations. The late spring cycles on these slopes are yet to come, awaiting the next warmup.

Outlook:

The late and cool spring continues, but it seems to be catching up, with very rapid thawing and melting to pass elevations. Backcountry travelers should beware of possible wet slabs atmid elevations, higher on solar aspects. They may not be releasing on their own, but could well be triggerable, especially on warm days.

Higher elevations need careful watching as they begin to thaw. Slopes that are difficult to trigger while cold will transition rapidly into instability as they thaw.

Choose terrain with care.That said, we found excellent slushy corn snow, without any rotten “facet factory” soft spots, other than near rocks, trees, or bare ground. Conditions are good for riding mellow slopes on the pass right now.

Take care, ride hard, die old!

Shgagwei, Lkoot Kwáan, Lingít Aaní.

Yesterday's rain and this week's thaw have rapidly thinned and wetted the snowpack on the pass. These glide zones above Glacier station usually have thick snow that produces glide avalanches to just above the tracks, but this year, the snow has thinned so rapidly that only small chunks are gliding away.

Our 13.8 Mile glide zone, on the other hand, is still frozen in under thick water ice from the cold winter, leaving us wondering when and if it may come down. We will continue to monitor it closely.

Only one small water ice chunk remains on the 15.2 Mile path, and Slippery Rock is clear.

On the pass, the American Shed path is partially melted out already, Hannan Shed is thin, and the snow in most areas, including the highway paths, has rapidly melted and settled into an early summer state in just this last week.

Higher elevations, though, are just going through the thaw and will be going through springtime instability over the next month, so take care with your terrain choices. Remember, this winter's snowpack is unusually weak and is not behaving like what we are used to, and exercise extra caution. Take care, ride hard, die old!

Shgagwei, Lkoot Kw'aan, Lingít Aaní.