The word on the street is Friday’s wind event…. Very strong winds from the West and South did a number to the snow surface, the snowpack and triggered numerous natural wind slab avalanches. Certain areas are stripped to the ground while others have sastrugi and rock hard wind drifts 2-3′ thick. In general, many slopes sport a variety of 4-8″ supportable wind slabs, thinner breakable wind crusts and even some soft snow in between. Don’t get too down though, there are zones that managed to survive and harbor soft settled snow, but folks seem a bit reluctant to give up the coordinates. The clear (but warm) weather forecast for the next week may start eating away at the hard surfaces and riding conditions could improve. (Check out what folks reported yesterday HERE.)
PERSISTENT SLAB AVALANCHES (In our current case: Hard WIND SLABS SITTING ON WEAK SNOW):
What to keep in mind and watch for:
It may be a busy New Year’s Day – remember safe travel protocols:
Photo below: Wind damage and older avalanche activity on Magnum’s NW shoulder
Large natural wind slab avalanche from Friday on the Northerly aspect of Magnum (back along ridge toward Taylor Pass). Crown mostly filled in, debris ran up other side of creek bed near common up-track to Taylor Pass.
Illustrating the complex nature of our snowpack and multiple weak layers: The Alaska Avlanche School Level 1 course had a CT (compression test) that resulted in three weak layers failing simultaneously on the 21st tap! This is a rare test result (top 2 layers were buried surface hoar and bottom layer was basal facets) Details HERE.
Summmit Lake area: Anti-tracks on Manitoba Mtn. Similar to scoured areas in Turnagain Pass. (photo J Haffener & S Galoob)
Watch for cornices in unusual places from the Dec 30 wind event. Though these may seem rock hard and welded into place, it’s good practice to always give them a wide berth – we do have warm, sunny weather on tap and this can help to weaken them.
Friday’s Southwesterly winds across Sunburst ridge attempted to strip the large cornices formed by the predominately Easterly winds.
Mostly overcast skies filled the area yesterday. Ridgetop winds were light from the South and West. Temperatures were in the upper 20's F on the ridgelines and lower 20's F in the parking lots.
Today, we should see sunny skies with WARM and breezy conditions. A very warm air mass is over us associated with a "Blocking High Pressure". Temperatures will be near 32F on the ridgelines and in valley bottoms a bit cooler, in the 20's F. Ridgetop winds are slated for 5-15mph from the South and West.
The high pressure in place looks to remain through the week. From the NWS: "there is high confidence in a prolonged dry spell over Southcentral Alaska and Kodiak Island, on the order of 7 days or longer". Yes, not anything snow lovers want to hear. The next chance for snow does not show up in the longer range model runs, yet - fingers crossed!
*The new year is creating a glitch in some weather stations reporting after 11pm.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880')||28||0||0||39|
|Summit Lake (1400')||16||0||0||12|
|Alyeska Mid (1700')||27||0||0||27|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400')||32||NE||5||19|
|05/18/21||Turnagain||Observation: Tincan Ridge||Joe Kurtak|
|04/30/21||Turnagain||Observation: Sunburst||W Wagner Forecaster|
|04/27/21||Turnagain||Observation: Tincan Ridge||Joe Kurtak|
|04/26/21||Turnagain||Observation: Magnum||Creighton/ Hoople|
|04/25/21||Turnagain||Observation: Sunburst||Nick D'Alessio|
|04/24/21||Turnagain||Observation: Airplane obs||Johnston-Bloom / DiJulia /Hilliard Forecaster|
|04/24/21||Turnagain||Observation: Corn biscuit||Heather Johnson|
|04/23/21||Turnagain||Avalanche: Lynx Ck Drainage||W Wagner Forecaster|
|04/23/21||Turnagain||Avalanche: Sunburst||Eeva Latosuo|
|04/23/21||Turnagain||Observation: Center Ridge Turnagain pass||Joe Kurtak|
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.