A series of warm and wet storms have created a widespread avalanche cycle across our forecast zone. Over the last three days 3.1 inches of rain has saturated the mid elevations (treeline zone) and rain/snow line has fluctuated between 2000’ and 3000’. A brief window of good visibility yesterday allowed for a look around Turnagain Pass where dozens of recent wet slab avalanches have occurred on all aspects below 3000’. These avalanches have been releasing near the ground on a well documented weak layer of faceted snow. The most interesting (and scary) avalanches observed yesterday were on the West facing terrain of Tincan below 2500’, an area many folks go when the avalanche danger is elevated. This avalanche cycle speaks to the powerful nature of a saturated snowpack and is a reminder that even small terrain features are suspect. An avalanche of this kind, if triggering from below or in a terrain trap, would be unsurvivable. Today another .5” of rain is expected below 2000’ combined with moderate to strong Easterly winds. High avalanche danger will continue through today and will remain elevated until the snowpack has a chance to drain or freeze. Travel in avalanche terrain is not recommended.
Recent wet slab avalanches were observed yesterday afternoon on the West facing terrain of Tincan.
Recent avalanches on Northern and Western aspects of Corn Biscuit.
Dozens of slabs have ripped out to the ground on the SE face of Seattle Ridge and most of the gullies are filled with debris. As of yesterday the uptrack on Repeat Offender remained intact.
In the Alpine, wet and heavy snow is falling, which becomes drier with elevation. From our rainfall totals at the snow stations over the last three days, we can expect around 3’ of snow has accumulated in the alpine. Cornices are building and the weak pre-existing snowpack continues to be loaded. Storm snow avalanches that include storm slabs, wind slabs and cornice breaks all can be expected today at the high elevations. This snow may also overload and tip the balance of the weak snow sitting near the ground and create a very large avalanche, taking most of the snowpack with it. This size avalanche could run into the lower elevations in steep or channelled terrain.
Again, the message is simple for today, avoid avalanche terrain. This means steering clear of all slopes 30 degrees and steeper including your exposure to runout zones.
Yesterday another 0.5 € of rain fell in Turnagain Pass and .94 € of rain Girdwood. Temperatures remained above freezing, mid 40F’s at seal level and mid 30F’s at 1000′. Easterly ridge top winds averaged in the 20’s with gusts in the 60’s. Temps cooled briefly last night bringing snow/rain line to 1700′ where a few inches of wet snow has accumulated at mid elevation weather stations.
Today another 0.5 € of rain is expected throughout the day and rain/snow line is expected to be around 2000′. Easterly ridge top winds could range from 20-30mph with gusts in the 40’s. Tonight continued rain showers are expected.
Stormy weather in the form of rain showers and strong Easterly winds is anticipated through Wednesday afternoon. Winds should diminish tomorrow afternoon and temperature will gradually start falling. Thursday into Friday we may see freezing temperatures again at sea level with a possibility of scattered rain and snow showers.
*Center Ridge snow depth at 6am is estimated due to depth guage sensor experiencing noise.
** Sunburst weather station data is from 6am – 8pm (12/11/17) due loss of battery power yesterday evening.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||34||3||0.5||*28|
|Summit Lake (1400′)||34||0||0.1||9|
|Alyeska Mid (1700′)||35||2||.94||16|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||30||ESE||21||50|
|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.