A layer of feeble, faceted snow that made up last week’s surface continued to show signs of activity yesterday both in our snowpits and on our tour up Tin Can. With 20- 24” of storm snow deposited upon this layer on Monday, natural avalanches are becoming less common but the poor structure of our snowpack is still proving ripe for human-triggered avalanches in the 2’ range, particularly near treeline. Above about 3,000’ slabs may be thicker than 2’ as moderate to strong winds blowing from the NE loaded many leeward slopes yesterday.
The snow below tree line is quite heavy and still very active. Extra caution is warranted as you travel through areas such as Tin Can trees or Eddies where you may encounter short, steep rollovers ending in terrain traps. Small slopes are holding enough snow right now to bury a person. Watch your slope angles (keep it sub 35*) and run out zones. This will be extra important as you encounter other groups in the backcountry today vying for similar terrain.
Winds were moderate to strong from the northeast yesterday with visible plumes of snow erupting off of ridges. In addition to loading south and west aspects the wind all but erased any signs of tracks or crown faces from Tuesday. Given the structure discussed above, Monday’s storm combined with stiff winds yesterday are likely to have formed slabs 2’ or greater in the alpine today. A stiff, drum-like surface, shooting cracks or whumphing will be indicators that you are dealing with a potentially unstable wind slab in the alpine. Again, effectively managing your terrain and avoiding steep slopes will be key today.
Steady rain around Girdwood and the Turnagain arm gave way to partial clearing on Turnagain pass mid-day yesterday. The rain snow line was observed to be around 1500′ with temperatures in the mid to high 30’s at Turnagain pass (1,000′). Winds were moderate to strong at times, gusting into the 50’s and 60’s from the northeast (see photo below). Snow accumulation around the Pass was minimal (~2 €) with new snow struggling to keep up with the impressive settlement rates of Monday’s storm
Today we can expect temperatures again to be in the mid to high 30’s at 1,000′ and winds from the northeast, backing off slightly ahead of an approaching short-lived high pressure system that will begin to set up tonight. A few showers this morning may add an inch or two of snow but the general theme for the day will be one of clearing.
We’ll start the weekend with clear skies tomorrow and then clouds building back in by Saturday as a weak north Pacific low moves into the eastern Gulf of Alaska.
Sticky surface snow and strong winds lead to wind-initiated roller balls at treeline on Tin Can. photo: John Sykes
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||36||2||.2||55|
|Summit Lake (1400′)||37||0||0||13|
|Alyeska Mid (1700′)||35||0||.24||36|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||29||n/a||17||73|
|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.