After two warm Pacific storms moved through over the weekend, it seems we will get a break in weather for the next few days. Precipitation and snowfall totals from Friday through this morning are listed below. The numbers are in ‘water equivalent’. The rain/snow line has been fluctuating between 1,000′ and 2,000′ during this three-day stretch.
Friday Saturday Sunday STORM TOTAL
Turnagain Pass 1.1 + 0.4 + 1.4 = 2.9″ water equivalent (~20″ dense snow)
Girdwood Valley 0.7 + 1.2 + 0.8 = 2.7″ water equivalent (~20″ dense snow)
Summit Lake 0 + 0.1 + 0.1 = 0.2″ water equivalent (~2″ dense snow)
Due to very limited visibility yesterday, we do not have information for the Alpine elevations. We can expect however, with dryer snowfall (adding 10-12″ yesterday) at these higher elevations and strong winds, natural wind slab avalanches, as well as cornice falls, were occurring. With the possibility for clearing skies today, things to watch for will be wind slab avalanches and cornices. Keep in mind:
– Easterly ridgetop winds are forecast to remain strong enough to transport snow above treeline today (20-30mph)
– Although winds are generally Easterly, they can be channeled by the terrain and load, or cross-load, a variety of aspects
– Watch for, and steer clear of, slopes being actively loaded
– Watch for smooth rounded surfaces and hollow feeling snow, stiff snow over softer snow
– Informal tests, such as sticking your boot (or pole) in the snow to feel if softer snow sits under stiffer snow, can be great ways to assess if there is a wind slab. This should be done on low angle slopes without avalanche potential before venturing onto steeper terrain.
Cornices have grown considerably during the past few weeks. Not only do they have the potential to fall naturally, but also to be triggered by the weight of a person or snowmachine. They can also trigger an avalanche below and, all in all, be VERY dangerous. Travel under or on them should be avoided. And remember, they have the tendency to break farther back from the ridge than expected.
Glide cracks have been appearing throughout Turnagain Pass over the last couple weeks. As you travel through the backcounty this week, pay attention for large open cracks in the snow, ‘crevasse looking’ features, these can release spontaneously without any warning. Similar to managing cornices, it is best to avoid traveling on or under slopes with glide cracks.
Photo below was sent to us yesterday from Turnagain Pass. These glide cracks are in the Treeline elevation band (between 1,000′ and 2,500′). Although the cracks are slightly obscured by yesterday’s snowfall, you can still see them looming.
Yesterday’s pulse of moisture ended up being a bit more potent than forecast, as mentioned above. Turnagain Pass saw roughly 10-12″ of snowfall above 2,500′ and rain at the road elevation. Along with the snow and rain, ridgetop winds were strong, blowing in the 30’s and 40’s mph with gusts over 70mph. Temperatures were warm, 37F at 1,000′ with a rain/snow line hovering right around 1,600′ (give or take).
Today we should see skies begin to breakup and precipitation to continue to diminish. Ridgetop winds, on the other hand, are forecast to remain moderate to strong from the East – averaging in the 20-30’s with stronger gusts. Temperatures will remain warm as well, in the mid 20’s F on the ridgetops and near 35F at 1,000′.
Tuesday through Thursday it looks like we should have a break between storms. Temperatures are forecast to cool slightly, skies clear off and winds shift to a Northerly direction. Stay tuned.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||31||8||1.4||91|
|Summit Lake (1400′)||35||1||0.1||27|
|Alyeska Mid (1700′)||33||1||0.75||64|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||27||N/A||N/A||N/A|
|05/06/20||Turnagain||Avalanche: Pastoral Peak, north face||Andy Duenow|
|04/10/20||Turnagain||Avalanche: Wolverine||Mike Records|
|04/10/20||Turnagain||Observation: Eddies lookers right shoulder||Matt Yoder|
|04/09/20||Turnagain||Observation: Bench Peak||Mike Records|
|04/04/20||Turnagain||Observation: Pete’s North||Anonymous|
|03/26/20||Turnagain||Avalanche: Tincan – Proper (SW facing)||CNFAIC Staff|
|03/26/20||Turnagain||Avalanche: Seattle Ridge||W Wagner Forecaster|
|03/25/20||Turnagain||Avalanche: Sunburst Uptrack @ 2000′||J. Boisvert|
|03/24/20||Turnagain||Observation: Turnagain – Road Observations||W Wagner Forecaster|
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.