General Late Spring to Early Summer Avalanche Advisory
Avalanches can occur year-round in Southcentral Alaska, and will occur in earnest through early June as the mountains undergo their annual “shed cycle.”
Significant wet avalanche activity has occurred recently on all aspects due to prolonged above freezing temperatures, rain, and only superficial (if any) nightly re-freeze into the upper elevations. A significant snowpack remains and there’s potential for a return to more wintry conditions with additional snowfall before summer arrives.
Make sure you know how to identify and avoid potentially dangerous avalanche terrain if you recreate in the mountains. This includes being aware of overhead avalanche danger even if you’re on flat and snow-free terrain, as many popular trails in Chugach State Park are exposed to avalanche paths (e.g. Penguin Ridge, Indian Creek, Falls Creek, Powerline Trail, Little O’Malley gully, the last ~1.5 miles of South Fork Eagle River before the lakes).
As always, be alert to the red flags of avalanche danger and practice safe travel techniques for avalanche terrain.
Springtime avalanche conditions will vary in the coming weeks; utilize prior advisories and the resources below to better understand late-season avalanche danger and the conditions that might be encountered. In general, avalanche danger is lower with colder (below freezing) temperatures and increases with rising (above freezing) temperatures and solar radiation (i.e. direct sunshine on slopes).
Spring Avalanche Conditions Forecasting Guide
Follow the links for further reading.
All Melt, No Freeze: generally above freezing temperatures day and night with widespread wet avalanche danger that exists at all times, but increases further with daytime warming and rain on snow. This is basically what we’ve been dealing with for the past week and a half.
Melt-Freeze Cycles: clear and cold nights freeze the snowpack into a supportable crust that gradually softens through the day, and often becomes isothermal (unsupportable and unpleasant for travel) in the afternoon. Avalanche danger increases through the day (as temperatures rise above freezing and solar radiation intensifies) and decreases at night with darkness, cooling, and re-freezing of wet snow. Ripe “corn” (that makes for good skiing) depends on aspect and timing. This weekend we expect a return to melt-freeze cycles.
All Freeze, No Melt: unseasonably cold temperatures freeze the snowpack into a supportable crust, with limited daytime melting and softening. Avalanche danger is reduced until temperatures and solar radiation increase. “Slide-for-life conditions” may be more of a hazard than avalanches, as the snow surface is very firm potentially making a fall on steep terrain difficult (if not impossible) to arrest.
Cold & Snowy: a cold spring storm can produce wintry weather. Widespread surface instabilities can develop from new snow. Widespread wet avalanche activity occurs when fresh snow is exposed to the sun and temperatures rise.
Check weather resources to better understand what scenario is most likely to exist at a given time.
Here are some important considerations when making plans to recreate this spring and early summer:
- Does your route cross avalanche terrain? Don’t forget to consider run-out zones (that might even be flat and snow-free), from gullies and upper elevation slopes, especially if they could channel long-running avalanches that release in the upper elevations.
- Be on the lookout for recent (and perhaps even active) avalanche activity; this is an obvious warning to stay away from avalanche terrain and run-out zones (aka avalanche paths).
- Pay attention to the sun! The sun can heat up steep, solar aspects significantly. This can change conditions from generally safe to generally dangerous very rapidly.
- Be mindful of terrain traps that could make even a small avalanche’s debris pile up deeply enough to bury a person, cause a dangerous fall or loss of control, or cause a traumatic injury. Learn from this report of a local high school teacher that died from a relatively small wet avalanche on Bird Ridge.
- Persistent weak layers will continue to produce large slab avalanches through “shed season.” As is the norm, the 2019-20 Chugach State Park snowpack developed widespread persistent weak layers. Most notably, a nasty layer of facets developed during the very cold and dry month of January. The typical depth hoar and basal facets developed near the ground. Recent natural wet slab avalanches failing on these persistent weak layers have been observed across the park, in some cases triggered by small (and seemingly insignificant) wet loose avalanches (aka point releases).
- Be mindful of how wet and saturated the snow is. If you’re traveling on snow, especially in avalanche terrain (i.e. terrain steeper than 30 degrees, or in the run-out/path of terrain steeper than 30 degrees), how wet is the snow? If there’s a supportable crust from recent freezing, avalanche danger will be lower (but keep in mind that steep, solar aspects above may be significantly more dangerous). If the snowpack is soft and mushy, especially if it’s unsupportable and you’re punching through or “postholing” due to isothermal conditions, steep terrain and the runout of steep terrain will be dangerous.
- Rockfall is rampant in the spring and early summer! Wear a helmet around steep, rocky terrain (especially if channeled – like a couloir). Be alert to warming temperatures and sunshine, especially after a fresh snowfall, that could trigger rockfall.
__________
Many avalanche accidents that have happened in Anchorage’s backyard of Chugach State Park could have been prevented by basic avalanche awareness. This level of awareness can be gained through a free or low-cost class. If you missed the many opportunities offered this season, make sure you take advantage of those that will be offered next season. In the meantime, you can start learning with free online resources here. Getting avalanche education is a big part of recreating safely on your vast and wondrous public lands, and being able to enjoy the mountains during the snow season will greatly enhance your life.
Here are links to further information on fatal avalanche accidents in Chugach State Park. You can learn from others’ mistakes.
__________
This concludes the Anchorage Avalanche Center’s eighth season of providing an entirely pro bono and grassroots backcountry snow safety program for the Western Chugach Mountains of Chugach State Park.
Chugach State Park needs a professional avalanche forecasting program. There is no comparable avalanche terrain in such close proximity to a large population of recreationists that lacks such a program anywhere else in the developed world. Anchorage deserves better.
Unfortunately, the Alaskan avalanche community has been plagued by divisiveness, entitlement, and dysfunction for many years. This has stifled the development of statewide public backcountry avalanche forecasting programs. Navigating Alaskan avalanche politics has been a significant component of this project since it began as a Master’s thesis in Outdoor and Environmental Education in 2012. A brief overview of these issues is provided by this paper, which was presented at the 2014 International Snow Science Workshop.
The minimalist and grassroots model of the Anchorage Avalanche Center could function sustainably with a seasonal budget that is about one-third of a Park Ranger’s annual salary. This is also discussed in the aforementioned paper. This project has proven that a seasonal operating budget of only $20,000-30,000 is necessary for long term sustainability.
In contrast, the Chugach National Forest Avalanche Information Center (CNFAIC) based in Girdwood has a seasonal operating budget of ~$200,000 (sourced from their annual reports) plus in-kind support and the infrastructure of the federal government via the US Forest Service. Yet, they only provide info for a relatively small area (primarily Turnagain Pass) despite having considerably more funding than all the other avalanche centers in the state COMBINED (Anchorage, Hatcher Pass, Valdez, Cordova, Haines, and Eastern AK Range).
The CNFAIC only supports a public observations platform for the Western Chugach Mountains of Chugach State Park and has even gone so far as to work against this project by refusing to acknowledge it as a resource to the public while marketing their website and observations platform as the only legitimate source of info for backcountry snow conditions in the Western Chugach. This has been extremely frustrating, especially when considering that CNFAIC staff has limited experience with the terrain and snowpack of Alaska’s mountains outside their area of focus (Turnagain Pass). While they provide commendable programming for Turnagain Pass, CNFAIC staff has overstepped their bounds by positioning themselves as the primary backcountry snow experts in the state.
The Anchorage Avalanche Center has reached out to the CNFAIC every season, in hopes of working with them constructively to improve avalanche information programming for the Western Chugach (as well as statewide). A few years ago, we sent this letter to all identified stakeholders that might be interested in supporting the project to develop a sustainable avalanche information program for the Western Chugach. It was ignored by the CNFAIC.
We applaud the CNFAIC’s work to develop a sustainable backcountry avalanche program for Turnagain Pass, as well as the development of a quality observations platform for the Southcentral Alaska region. We encourage them to put personalities and egos aside, and work with us via an eye-level relationship based on mutual respect toward improving avalanche information programming for the greater Anchorage area. We also encourage them to prioritize working with multiple parties throughout the state toward the development of the most efficient and effective paradigm for statewide avalanche info, over securing funds only for their program (and the limited terrain it serves).
If you think the Western Chugach Mountains of Chugach State Park need more than just a public observations platform, please consider getting involved with (or donating to) the Anchorage Avalanche Center effort. Solicit support from your government representatives, the Department of Natural Resources (Alaska State Parks/Chugach State Park), and local businesses and organizations relevant to snow-season backcountry recreation. Your help is appreciated, and imperative for the development of sustainable avalanche information programs in The Greatland.