A modest amount of snow combined with winds will add stress to a snowpack that is hanging in the balance. Fresh slabs up to 1’ thick on steep leeward slopes in the Alpine have the potential to release on their own. Given the warm temps and high level of moisture in the new snow, many of these slabs will “stick” well to underlying surfaces. Because of this it will take steeper slopes, over 35 degrees, to get slabs to move. This concern will be more pronounced where winds are actively loading slopes. These slabs also have the potential to step down into deeper layers in the snowpack.
Snow that feels stiff, sounds hollow or produces shooting cracks and is connected to steeper terrain should be avoided today.
A layer of weak faceted snow sits anywhere from 6” to 3’ below the surface. This layer continues to be reactive in tests. Average slab depths in the Alpine prior to this current storm were 2 feet. Adding into the equation another slab makes this avalanche concern a higher priority in terms of consequences. While it may be more difficult for humans to trigger a slab at this depth, the potential still exists. This layer has also shown high propagation potential. Avalanches occuring at this layer have the potential to pull out across large areas.
Because of this potential travel in avalanche terrain is not recommended today.
Rain will weaken the snow surface today. Should the rain/snow line creep above the 2,000’ level, there is potential for wet slab avalanche activity. Below 2,000’ wet loose avalanches are possible in steep terrain. Volume will be generally low. Pay attention to the terrain below you, as terrain traps such as cliffs, gullies, and trees will increase the consequences of being caught in relatively small wet loose avalanches today.
Yesterday saw the beginning of a surge of moisture spreading across the forecast area. Warm, wet and windy was the general theme. Ridgetop temperatures were in the high 20s F and low 40s F at sea level. Precipitation began by late morning with the rain/snow line hovering around the 2,000′ level. Below this line rain fell with the Girdwood Valley receiving .5 € and Turnagain Pass picking up .3 €. Snowfall amounts above the rain/snow line range from 3-5 €. Ridgetop winds have been moderate with Seattle Ridge blowing in the 30-40 mph range.
Southerly flow will continue to impact the area today with more of the same. Precipitation amounts will be around .5 € of H20, with snowfall in the 3-5 € range. The rain/snow line will be around the 2,000′ mark. Winds will be out of the East at 25-35 mph. Temperatures will climb to 40 F at 1,000′.
The extended outlook is showing a continuation of this warm, wet and windy pattern through the weekend. Intensity will diminish by tonight, but showery conditions will persist through Sunday and into the early part of next week.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||33||2/rain||.2||43|
|Summit Lake (1400′)||37||rain||.1||8|
|Alyeska Mid (1700′)||35||rain||.5||24|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||29||n/a||30||67|
|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|
|04/15/21||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|
|04/10/21||Turnagain||Observation: north sides||lance breeding|
|04/09/21||Turnagain||Observation: Girdwood to Turnagain Road Observations||W Wagner Forecaster|
|04/05/21||Turnagain||Avalanche: Resort bowl Seattle creek head wall||Clint Kyffin|
|04/04/21||Turnagain||Observation: Center Ridge||Andy Moderow|
|04/03/21||Turnagain||Observation: Repeat Offender – Seattle Ridge||Troy Tempel|
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.