There were a couple reports of people triggering small slabs on wind-loaded slopes yesterday, one skier and one snowmachiner. The 1-2′ of snow that fell at the end of last week loaded a layer of widespread surface hoar, that was buried on January 21st. There were a number of human triggered avalanches over the weekend but overall the storm snow has only been acting as a slab in areas that were affected by wind. This continues to be the case. The slides yesterday occurred in the Johnson Pass area and on Eddies. One group investigated and found that the weak layer in the slide they triggered was the January 21st buried surface hoar underneath wind-affected slab. This is a good reminder that despite the cold and clear weather now slowly faceting away the slabs; there is still the possibility of finding and triggering lingering slabs in leeward terrain today. Remember that the surface hoar is lurking underneath the recent snow and it’s important to assess areas affected by wind. Slabs can be deeper in loaded areas. Pay attention to slopes where the snow feels stiff, looks pillowed or sounds hollow and watch for shooting cracks. A small slab in the wrong terrain could have high consequences.
Small slab in the Johnson Pass area, intentionally triggered in a ‘sled cut’ yesterday.
It is important to keep this snowpack structure in mind today on slopes with wind-affected snow. Buried surface hoar could be underneath.
These avalanches occurred on Eddies Saturday and were remote triggered from the ridge. They were noted again yesterday by a party in the area that had a ski cut produce a slab, 16″ deep and 30′ wide in similar terrain, that ran to the bench below. Photo: Joe Engel
As the cold weather continues to loosen and facet the surface snow, loose snow avalanches (sluffs) are becoming larger and faster by the day. Watch out for and manage your sluff in steep terrain features protected from wind.
Triggering a deep slab is becoming unlikely, but is still not out of the question above 3000′. In the high elevation snowpack there are a variety of weak layers in the mid pack and near the ground. Because of this poor structure, there is still a chance of triggering a deep slab if you find the wrong spot. The most likely trigger spots are in thin areas in the snow cover, often near rocks, or where the slope rolls over.
Yesterday was clear and sunny. Temperatures were in the single digits to mid teens. Winds were easterly and picked up a little in the afternoon gusting as high as 20 mph. Overnight the skies became partly cloudy.
Today skies will be mostly to partly cloudy. Winds are forecast to be calm and temperatures will be in the mid to high teens. Skies will become clear again overnight.
This weather pattern will persist into the weekend with more sunshine, cold temperatures and calm winds. From the NWS, the “blocky” pattern aloft maintains it`s hold over the regional weather pattern. There is still discussion of a pattern shift but a lot of uncertainty about timing and how much it will impact this region.
PRECIPITATION 24-hour data (6am – 6am)
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||14||0||0||65|
|Summit Lake (1400′)||4||0||0||18|
|Alyeska Mid (1700′)||10||0||0||52|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||11||ESE||9||19|
|01/25/20||Turnagain||Observation: Magnum||Ryan Van Luit Forecaster|
|01/25/20||Turnagain||Observation: Tincan||Eric Roberts/ Kakiko|
|01/23/20||Turnagain||Observation: TIncan||Eric Roberts|
|01/23/20||Turnagain||Observation: Goldpan||Allen Dahl|
|01/22/20||Turnagain||Observation: Sunburst||Adrian Beebee|
|01/22/20||Turnagain||Observation: Sunburst||Ryan Van Luit Forecaster|
|01/22/20||Turnagain||Observation: Seattle Ridge||W Wagner Forecaster|
|01/22/20||Turnagain||Observation: Tincan||Allen Dahl|
|01/21/20||Turnagain||Observation: Tincan||Eric Roberts|
|01/20/20||Turnagain||Observation: Eddies||H. Thamm B. Edwards|
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.