Chugach State Park

Recent Avalanches: Over the past week, we have had four observations in the Chugach State Park with seven documented natural avalanches—primarily in the South Fork of Eagle River between February 12th and February 14th, with one reported avalanche in Bear Valley (above Nickleen Drive). One of the avalanches hit the Hiland Road.  The start zones of all the avalanches ranged between 3,300′ to 3,700′ on W, NW, and NE aspects. From the observations, it looked like the avalanches were all wind triggered slab avalanches that we suspect broke on a weak layer within the snow. However, seeing the avalanche crown lines was difficult because the wind filled them back in so quickly. It is worth noting that a few of these avalanches were large enough to bury a person. To read more about the avalanches in the South Fork of Eagle River—check out this observation.

The forecasting team relies heavily on public observations, and we always appreciate any information you all have to share. It takes a community to make an avalanche center run. Thank you!

Weather Recap: This week’s theme has been high winds and warming temperatures. We had a significant wind event that started Monday morning and eased off a bit Wednesday afternoon. Upper elevations have stayed breezy for the remainder of the week. The southeasterly event and pattern for the week brought sustained 25 to 50 mph winds with gusts up to 85 mph. Temperatures ranged from 15 F to 49 F with an average of around 30 F, a warmup from the temperatures we have seen over the last couple of weeks. A trace to an inch of snow fell last weekend in the Outlook area.

Snow depth remains variable across the range. Moving forward, it is the time of year to start tracking surface conditions on southerly slopes as warm temperatures and solar radiation may start to form melt-freeze crusts.

Weather Forecast: Skies should stay clear overnight tonight with lows in the mid-20s F. Southeast winds today were blowing 10 to 15 mph with gusts into the 20s and are forecast to continue until Saturday evening, becoming light overnight through Sunday. Clouds are expected to move in Saturday and increase, becoming overcast with a chance of snow Sunday into Monday. The unsettled weather pattern looks to continue into the week, with light snow and the potential for rain. Temperatures will be in the mid-20s to mid-30s F.

The natural avalanche that buried Hiland Road on 2.12.24. Photo: Peter Wadsworth 2.13.24

Natural avalanche in South Fork of Eagle River between Solstice Gully and Swiss Bowl. Photo: Peter Wadsworth 2.13.24

Staying on brand for the Front Range, the winds over the past week are the main story going into the weekend. In addition to triggering a few natural avalanches, the southeasterly winds were strong enough to scour into old wind-affected snow and redistribute it onto leeward slopes. The wind effect is clearly obvious when looking around the mountains. If venturing out to give the wind blasted surface conditions a try, triggering wind slab in steep, loaded terrain may be possible. Pay attention to any hollow-sounding snow (indicating weak or softer snow below), look for shooting cracks and remember you could be well out onto a slope before it fails. This much wind effect often makes slabs very stubborn to trigger but could catch you off guard if they happen to release. A wind slab avalanche could also step down and fail on one of the buried weak layers in the snowpack resulting in an larger avalanche (see Problem 2).

Wind scoured ridges and wind-loaded features in Two Bowls. Photo: Peter Wadsworth 2.13.24

Not to sound like a broken record but… We are still worried about a few different persistent weak layers buried in the snowpack. The larger avalanches that were triggered by the winds this week were deep enough to have likely failed on one of the layers of buried near-surface facets we have been talking about for weeks. An observer this week in the South Fork of Eagle River reported experiencing two larger collapses (whumpfs) while skinning, which is also usually attributed to weak snow falling below a slab. This prompted the observer to turn tail and ski back to the car. There is also a weak layer of snow at the base of the snowpack that has been observed in some higher elevation snow pits. Persistent slab avalanches are often triggered from thin spots in the snowpack where the weight of a person can impact the weak layer and cause a failure. It’s not always the first person on the slope with a set-up like this that triggers the avalanche—it could be the fifth or tenth.  Triggering an avalanche that fails on one of these buried weak layers remains a concern and should be part of the terrain choice decision-making this weekend.

Hunter Pass snow pit. 2.12.24