Skiers triggered small avalanches up to 6″ deep on wind-loaded slopes on Notch Mtn. and in Eddies yesterday. These were not big enough to bury a person.
|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|
A storm system is bringing 2-4″ of heavy snow with strong winds, building sensitive wind slabs on top of low-density snow from the first part of this week. A fragile setup on its own, this upside-down combination is also sitting on top of various weak layers including surface hoar up to around 1700-2000’, and near-surface facets up to ridgetops. Today it will be possible for a person to trigger an avalanche up to a foot deep in wind-loaded areas below ridgetops and convex rollovers, or in cross-loaded gullies. Be sure to pay attention to clear signs of unstable snow like cracking, collapsing, and fresh slab avalanches as the active weather continues today. If you see any of these red flags, you can stay out of harm’s way by avoiding traveling on or below steep wind-loaded slopes. As of this morning, weather models are still mixed on the timing and amount of snowfall expected with this storm. Pay attention to changing conditions as it develops– if we do end up getting more snow, avalanche conditions will become more dangerous. The rain level is expected to rise later today and into tonight, but it should stay below 1000’.
Cornices: Give cornices plenty of space as they can break farther back than you might think. Be mindful while traveling below them, minimizing your time spent underneath them.
Loose Snow Avalanches: Be aware of loose snow avalanches in steep terrain. While it is not likely they would be big enough to bury you, they can pick up enough volume and momentum to carry you and can be a serious issue in consequential terrain. These will be dry snow for most elevations, but we could see some loose wet avalanches below 800 feet as the rain level moves up later today.
The Dec. 1 rain crust/facet layer is buried 3-5’ deep, and appears to be weakest on the non-motorized side of Turnagain pass. It hasn’t gone anywhere, but with the current snowpack structure it is very unlikely a human could trigger an avalanche on this layer. We will continue to track this layer, but it will not be a major concern until we get a heavy load of snow or rain, or this weak layer becomes even weaker.
Yesterday: After a brief snow shower in the morning, with rain up to around 500’, cloudy skies gradually broke up throughout the day. Easterly ridgetop winds were blowing 10-25 mph with gusts to 47 mph. Ridgetop temperatures rose to the mid- to upper 20’s during the day, with daytime highs in the low 30’s at lower elevations.
Today: We are expecting to see 2-4″ of heavy snow, with ridgetop temperatures in the mid-20’s F and highs reaching the low 30’s at lower elevations. Rain line is expected to stay around 500′ during the day today. Easterly ridgetop winds are expected to blow at 25-35 mph with gusts to 45 mph.
Tomorrow: Snowfall and strong winds will continue tonight, with another 6-9″ possible by tomorrow morning, and a few more inches possible during the day tomorrow. We are expecting sustained easterly winds at 30-40 mph at ridgetops starting tonight and continuing through tomorrow. Temperatures will stay in the mid- 20’s to low 30’s tonight, and the rain line is expected to move up to around 800′ overnight.
PRECIPITATION 24-hour data (6am – 6am)
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||29||0||0||74|
|Summit Lake (1400′)||28||0||0||30|
|Alyeska Mid (1700′)||30||2||0.15||78|
RIDGETOP 24-hour data (6am – 6am)
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||24||SE||9||23|
*Winds have been around 20-30 mph with gusts in the mid-30’s to mid-40’s since 3:00 a.m.
|04/21/21||Turnagain||Observation: Sunburst||Schauer/ Behney Forecaster|
|04/19/21||Turnagain||Avalanche: Triangle, Seattle creek||Will Morrison|
|04/18/21||Turnagain||Avalanche: Turnagain Pass Road Obs||Andy Moderow|
|04/18/21||Turnagain||Observation: Seattle Ridge, approximately 300 yards south of the up track||Brent Byrne|
|04/17/21||Turnagain||Avalanche: Road obs||Johnston-Bloom / Moderow Forecaster|
|04/16/21||Turnagain||Avalanche: Seattle Ridge||Wendy Wagner Forecaster|
|04/16/21||Turnagain||Avalanche: Turnagain Pass, non-motorized side seen from Seattle Ridge||CNFAIC Staff Forecaster|
|04/16/21||Turnagain||Observation: Sunburst||Lance breeding|
|04/15/21||Turnagain||Observation: Tincan||Schauer/ Rothman Forecaster|
|04/13/21||Turnagain||Observation: Turnagain Pass Road Obs||A Schauer 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: 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.