New snow and wind have combined to create very unstable slabs in the 8-12” range. Ridgetop winds have picked up into the 40 mph range out of the East/Southeast overnight and will remain strong through the day. An additional 10-12” of snow and, more importantly, 1” of H20 forecasted for the higher elevations will increase the size of these slabs into the 2 foot range. These slabs will release naturally in some locations and will be very sensitive to human triggers. Rapid loading that occurred overnight and will continue throughout the day is enough of a trigger to initiate avalanches.
This is not a complicated situation. Avoidance of avalanche terrain is the only way to “manage” this problem today.
A layer of weak snow that sits anywhere from 8” to 3 feet below the surface is the most concerning layer today. Avalanches occurring in the upper layers have the potential to step down to this layer. In cases where this happens, the volume will be large and potential for burial, if caught, is high. Avalanches occurring at this layer have a high propagation potential, which means that fractures can and will travel across slopes and over long distances.
Because of this travel in avalanche terrain is not recommended today (have I mentioned that already?). While this problem exists mainly in the Alpine elevations, it will be important to avoid the runout of terrain from above when traveling in the Treeline elevations.
Rain falling on snow as high as 2,000’ will weaken the surface snow. This will result mainly in wet loose avalanches. Volume will be generally low, as the snow in the mid and lower elevations has already been hit with periods of rain over the past few days and has had time to adjust. With that being said, it will be important to avoid steep terrain where the surface snow is wet. If you find yourself sinking through the snow deeper than your boot it is time to move to lower angled terrain. Consequences of wet loose surface snow moving will become high if pushed into or over terrain traps such as cliffs, gullies, glide cracks, or trees.
Yesterday brought a continuation of warm, wet and windy weather to the area. Temperatures were in the mid 20s F along ridgetops. Temps at sea level climbed into the high 30s – low 40s F. A mix of rain and snow have been falling with the Center Ridge SNOTEL site picking up 5 € of snow containing .5 € of H20. The rain/snow line fluctuated and was around the 1,800′ mark for most of the 24 hour period. Winds cranked back up with Sunburst averaging in the 30 mph range with a max gust of 96 mph.
A strong surface low currently parked just south of the Alaska Peninsula is pulling a warm stream of moisture from the South over the area. Today will bring intense periods of precipitation and high winds, with an additional 10-12 € of snow and 1 € of H20 above the rain/snow line. The rain/snow line should be around the 1,600′ mark. Winds will be strong out of the East at 40-50 mph. Temperatures will remain warm with ridgetops approaching 30 degrees F.
Wind and precipitation intensity should begin to taper off by tonight. Temperatures will cool slightly and a chance for showery precip will remain through the middle of the week.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||33||5||.5||39|
|Summit Lake (1400′)||36||rain||.1||9|
|Alyeska Mid (1700′)||33||2/rain||.4||27|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||27||SSE||27||63|
|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: 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.