Our current problem can be described as low probability/ high consequence. The likelihood of waking up this documented layer of buried surface hoar that we’ve been talking about the last few days is waning as time ticks by and temperatures drop. However if one were to find the right trigger point (shallow areas in the slab or slope convexities are the likely areas) on a slope the resulting avalanche could be quite large. We have a hard time classifying this type of problem using the North American Avalanche Danger Scale because it doesn’t totally capture this low likelihood/ high consequence scenario with any one color.
Colors aside, it’ll be important today to travel through the backcountry with heightened awareness. Ensure good spacing between parties and individuals when ascending steep terrain; one person at a time on the slope; plan out and communicate escape routes and safety zones; ensure safe zones are safe. Keep in mind that with this avalanche problem, potential exists for a slope to avalanche wall-to-wall or even connect slopes through shallow bands of rock.
As mentioned in the bottom line, this is a “scary” MODERATE avalanche problem and though our snowpack is gaining strength, surface hoar once buried accounts for more avalanche accidents than any other weak layer.
Calm weather dominated the eastern Turnagain arm zone yesterday. After a light morning drizzle deposited a very thin crust on the snow surface up to about 1,500′ the skies began to break and visibility improve. Ridgetop winds were in the single digits from the east with temperatures hovering around 32 degrees at 1,000′.
We may continue to see a few snow showers through the day as instability in our region weakens with an advancing ridge moving in from the west. This will shift winds to a northwesterly direction where we may see gusts into the mid-teens or low 20’s mph today. Temperatures at 1,000′ will linger right around the freezing mark. We may also see fog development today and into tomorrow-in low-lying areas around the highway.
Looking out toward Xmas it appears that south-central AK will be influenced by westerly flow as a dominant low-pressure system in the western Aleutians tracks east toward the mainland. Expect temperatures to slowly decline and periods of light snow thru the holiday.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||29||1||.1||28|
|Summit Lake (1400′)||24||0||0||4|
|Alyeska Mid (1700′)||32||1||.1||21|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||26||N/A||N/A||N/A|
|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|
|04/12/21||Turnagain||Observation: Tincan||Johnston-Bloom / Latosuo 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.