Over the past two days the mountains have been much quieter avalanche-wise. However, in the Summit Lake area south of the forecast zone two large natural wet slabs released on Butch Peak (likely 2 days ago on Thursday). Additionally, one human triggered wet sluff occurred in Lynx Creek yesterday (Friday).
One of two large wet slab natural avalanches in the Summit Lake area (Butch Peak, SW facing). These are believed to have released sometime Thursday 4.22 afternoon. Photo taken 4.23.21 by Alex McLain.
Wet loose avalanche triggered by a snowboarder on a thin steep rocky feature. Avalanche was small, but took the all the snow (2′ or so) that existed on this feature. Note that the other avalanche debris and roller balls are old – likely from a week ago. 4.23.21.
|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|
Triggering a wet loose avalanche is likely on steep slopes that have softened enough to harbor boot-top (or deeper) wet surface snow. These ‘sluffs’ could be small or large pending the size of the terrain. They could gouge down and take the whole snowpack if the conditions are right and especially if the snowpack is thinner. These types of avalanches are nothing to mess with and can be quite destructive. Wet slabs on slopes seeing significant warming will be possible to trigger and can be extremely destructive. They can, and often are, triggered by a wet loose avalanche. Wet slabs are most likely to occur in areas with a thinner snowpack, such as Summit Lake. Although natural wet loose and wet slab avalanches will be possible today, it’s the human triggered avalanches that will be likely. Hence the danger rising to CONSIDERABLE in step with daytime warming and sunshine.
Timing is everything… The goal for a fun day in the mountains is to catch the surface when it’s melted a few inches but not so much that your boot or snowmachine track is sinking way down into 10+” of mush. At this point, it’s time to head to another aspect. As we know, north and east aspects warm first, then south, then west, and last north gets the sun again this time of year. Paying close attention to how much wet snow exists on the slopes you encounter is key. Exit routes require thought as well. We don’t want to be forced into traveling under steep rocky terrain baking in the sun that could shed snow onto us.
Cornices: These features are oozing over in the warm temperatures and will become easier and easier to trigger as time goes on. Be aware to not accidentally travel onto one and limit any exposure under them.
After 8 days of unseasonably warm springtime temperatures bringing down the house, it looks as though the mountains are starting to adjust to the spring transition. In case you missed it, here’s a little video of the widespread natural avalanche cycle that occurred last weekend. Since then, we’ve seen a handful of natural glide avalanches, wet loose and wet slab avalanches. Most of the wet slabs are being seen in areas with a thinner snowpack, such as the Summit Lake area in the photo above. As we move forward, we are not out of the woods. Remember, large natural avalanches are still possible and human triggered avalanches likely. These could be significant enough to run into valley bottoms in areas with enough snow left on the mountainsides.
Playing the aspects for fun soft snow, but safe avalanche conditions. 2.23.21.
A big thank you to APU’s snow science course for not only assessing the corn skiing conditions on Sunburst yesterday, but for providing snowpack information throughout the season! See their pictures and comments below.
“Tricky skinning along the Sunburst lower ridge line. While during our tour avalanche hazard was low, sliding hazard was imminent. Time to think about self arrest skills, Whippet and potentially ski crampons!” 4.23.21. Eeva Latosuo.
“By 1:30pm surfaces started to soften up quite nicely as exemplified here: 2 cm paw penetration by 30lbs canine.” 4.23.21. Eeva Latosuo.
Glide avalanches are releasing as the entire snowpack warms up. This is the time to not trust any glide cracks and limit/avoid time under them. They are opening up and releasing around the region, including easily accessed areas such as the front side of Seattle Ridge.
Bears: In all seriousness, bears are waking up and folks have been seeing them roaming about. It’s a good thing we are trained to observe natural hazards and now we can add bears to the list.
Yesterday: Sunny skies with light easterly ridgetop winds were over the region. Temperatures warmed to the the low 40’sF along the higher peaks and between 55-60F in the lower and mid elevations.
Today: Another round of sunshine, light south to easterly ridgetop winds, and warm springtime temperatures is forecast. Overnight lows, last night, were in the 25-35F range in valley bottoms and in the 35-40F range in the mid and upper elevations. Daytime highs should be near 60F in the low elevations today and in the high 40’s F along the high ridgelines.
Tomorrow: Continued sunny skies and light east winds are expected until early next week as the blocking high pressure remains entrenched over Southcentral. Temperatures are expected to continue to drop into the 25-35F range overnight with clear skies in valley bottoms and increase through the day to near 60F in the low elevations and to the high 40’s F in the high elevations.
PRECIPITATION 24-hour data (6am – 6am)
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||43||0||0||96|
|Summit Lake (1400′)||40||0||0||32|
|Alyeska Mid (1700′)||45||0||0||108|
RIDGETOP 24-hour data (6am – 6am)
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||43||SE||4||10|
|05/17/22||Turnagain||Avalanche: Sunburst||CNFAIC Staff|
|05/17/22||Turnagain||Observation: Tincan Ridge||Joe Kurtak|
|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|
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: firstname.lastname@example.org
|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.