There were several near-misses yesterday in which skiers and snowmachiners triggered large avalanches. Luckily nobody was injured or killed. Here is what we saw:
Eddies: A skier triggered a large avalanche 1000′ wide, 3′ deep and running up to 1500′ while skinning up to the top of Eddie’s. The skier was caught and partially buried, but did not get carried for the entire path. Details here.
Seattle Ridge: We received multiple reports of snowmachine triggered avalanches on Seattle Ridge. Most of these appear to have been triggered remotely, and some were triggered after there were up to 10 sets of tracks on the slope. This includes avalanches in Little Sweeden, Widowmaker, Warmup bowl, and Triangle bowl. As far as we know nobody was caught in any of these avalanches. More details here and here.
Magnum: A skier triggered a large avalanche on the west face of Magnum. The skier was caught and carried, but was able to self-arrest before getting taken down the entire path. The avalanche appears to have been roughly 1000′ wide, running for about 1200′. Details here.
This avalanche in Triangle bowl released sympathetically with two other avalanches. The initial avalanche was triggered in Warmup bowl on a slope that already had 10 sets of tracks immediately adjacent to the slide. Photo: Warren Gage. 12.02.2021
|Signal Word||Size (D scale)||Simple Descriptor|
|Small||1||Unlikely to bury a person|
|Large||2||Can bury a person|
|Very Large||3||Can destroy a house|
|Historic||4 & 5||Can destroy part or all of a village|
Sometimes the mountains will softly whisper in our ears, giving us subtle clues that something is amiss. Other times they will shake us by the shoulders, slapping us across the face as they scream at us that we need to pay attention because conditions are dangerous. Yesterday was a case of the latter. We had reports of 7 human-triggered avalanches, all of which failed on weak, faceted snow buried 2-3′ deep. This includes a very large avalanche on Eddies (details here), 5 different large avalanches on Seattle ridge (details here and here), and a very large avalanche on Magnum. We also saw three large natural avalanches on Orca, which may have been a few days old but further demonstrate what the snowpack is capable of (details here).
There are a few things about the current snowpack that have our guard up. First of all, some of these avalanches are large- up to 1000′ wide and 3′ deep, propagating around significant terrain features. The second noteworthy detail is that a lot of these avalanches have been triggered remotely. This means a person can trigger an avalanche from below, adjacent to, or above a slope. The third issue is that we have seen avalanches failing after there were already multiple sets of tracks on a slope.
This type of avalanche problem can hang around for a while. It can also give us misleading or confusing feedback- the avalanche activity was noteworthy yesterday, but along with the handful of large avalanches were hundreds of tracks where people were getting into big terrain without consequence. The big takehome is that the snowpack is capable of producing large or very large avalanches, and people can trigger them. With another day of quiet weather today, we can expect to see similar conditions to what we saw yesterday. Luckily none of yesterday’s large avalanches resulted in injuries or worse. Today we all need to take a big step back with our terrain use and enjoy the soft snow on low-angle slopes, keeping an eye on our partners and being aware of the potential to remotely trigger an avalanche. There is still a whole lot of winter left, let’s all be patient and give this snowpack some time to heal.
We continue to monitor glide activity in the area. It looks like the glide avalanches have slowed down for now, but there are a lot of glide cracks around. Avoid spending time under these features since the can release unpredictably, and are very large and destructive when they do.
Yesterday: The weather was quiet yesterday, with highs in the single digits to mid teens F and overnight lows dropping to the single digits to low teens below 0 F. Winds were light with variable direction, and skies were mostly sunny for most of the day before fog rolled in later in the afternoon.
Today: We are expecting another day of cold and clear weather, with daytime highs in the single digits F and mostly sunny skies. Winds should be light out of the southwest at Turnagain Pass and out of the east/northeast near Girdwood. No precipitation is expected today.
Tomorrow: Lows should dip down to the single digits above and below 0 F tonight, before creeping up into the low teens F tomorrow. Cloud cover will increase during the day, but no precipitation is expected. Winds should be light out of the south. It is looking like Sunday night will be the soonest chance for another round of snow, with more active weather in the beginning of next week. Stay tuned for more.
PRECIPITATION 24-hour data (6am – 6am)
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||5||0||0||59|
|Summit Lake (1400′)||0||0||0||N/A|
|Alyeska Mid (1700′)||3||0||0||N/A|
RIDGETOP 24-hour data (6am – 6am)
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||4||NE||2||6|
|05/11/22||Turnagain||Avalanche: Cornbiscuit and Magnum west faces||CNFAIC Staff Forecaster|
|05/07/22||Turnagain||Observation: Granddaddy||Kit Barton|
|04/29/22||Turnagain||Observation: Sunburst wx station||AS/ MM/ AM/ NH|
|04/28/22||Turnagain||Observation: More Turnagain Pass/Summit Lake wet slab activity||Alex Marienthal|
|04/27/22||Turnagain||Observation: Magnum||Sykes / Buttrick Forecaster|
|04/27/22||Turnagain||Observation: Girdwood/Summit/Turnagain Road obs||A S|
|04/24/22||Turnagain||Avalanche: Seattle Ridge – large glide avalanche on Repeat Offender path||CNFAIC Staff Forecaster|
|04/24/22||Turnagain||Avalanche: Seattle Ridge uptrack||Martin Schmidt|
|04/24/22||Turnagain||Observation: Pastoral||Jason Konigsberg|
|04/24/22||Turnagain||Observation: Sunburst||Lance breeding|
Status of riding areas across the Chugach NF is managed by the Glacier and Seward Ranger Districts, not avalanche center staff. Riding area information is posted as a public service to our users and updated based on snow depth and snow density to prevent resource damage at trailhead locations. Riding area questions contact: email@example.com
|Area||Status||Weather & Riding Conditions|
This is a general backcountry avalanche advisory issued for Turnagain Arm with Turnagain Pass as the core advisory area. This advisory does not apply to highways, railroads or operating ski areas.