After a short break between storms over the weekend, we have another small system over us today that is a bit more ‘blow than snow’. So far only a couple inches of snow has fallen at Turnagain Pass but up to 6″ in the Girdwood Valley; we are expecting another 2-5″ to fall through the day above 1,000′. Ridgetop winds are the big player today and have increased into the strong category from the East. Add these winds to the new snow, and the existing soft snow available for transport, and we have a wind slab avalanche problem.
If you are headed out today, watch for areas of wind drifted snow and/or slopes that the winds are actively depositing snow. Traveling over wind drifts on gentle slopes and watching for cracks that shoot out from you is a great way to assess if these wind slabs are not bonding well and could avalanche if the slope is steep enough. Quick hand pits in these areas (stiffer snow over softer snow) are good tools as well.
Don’t forget, cornices are still falling and the weight of a person and/or snowmachine could help tip the balance. Give these guys a wider berth than you may think necessary along the ridgelines; many have grown to the point where it hard to determine where the ground ends and the cornice begins.
Photo Left: Northeast winds loading Southwest slopes late in the day yesterday, Magnum Ridge. Photo Right: Wind transport over Taylor Pass.
Two new glide avalanches were seen yesterday in the forecast region. The first was on Pete’s South and the second was in Skookum Valley (side note: if you are not familiar with the names at Turnagain Pass check out this map – maps are found under the resource tab!). Avoiding and limiting time under glide cracks is essential as these avalanches will destroy anything in their path. Many many cracks still litter the mid-elevation band at Turnagain Pass and surrounding regions.
Pete’s South glide avalanche pictured below, before and after the crack released. Photos Tim Glassett. Additional photos can found HERE.
Left, Glide Crack 1:37pm Sat. 2/6 Right, Crack released and avalanched sometime before 11:40am Sun. 2/7
Skookum glide avalanche, this slide can easily be seen from the Seward Highway as you pass the Portage Valley road.
We have been concerned about a layer of weak older snow that sits roughly 2′ below the surface. This older snow is essentially last week’s surface that became loose and started to facet before it was buried by 2-3′ of storm snow Feb 3-5th. Over the weekend, we have found that this old snow/new snow interface has bonded very well – great news. Report from yesterday’s investigation HERE. However, we have little to no data for areas South of the Pass, such as the high elevations above the Johnson Pass trail or Summit Lake. Hence, there may be areas that did not bond well and if this is the case large and ‘connected’ avalanches will be possible.
Partly cloudy skies and light winds covered the region yesterday morning. By the early afternoon, a weak low-pressure system began to move in bringing cloud cover and a bump in Easterly winds (~25mph averages) along the ridgetops. Temperatures remained mild in the 20’sF at the mid-elevations.
Overnight, we have seen an inch of new snow at Turnagain Pass with up to 6″ in the Girdwood Valley. The rain/snow line is currently ~500′ and may rise to 1,000′ by later today. We are expecting an additional 2-5″ at the higher elevations by 6pm. Winds will continue in the 20-30mph range from the East along the ridgetops and temperatures are expected to rise to the mid 30’s at 1,000′ and the mid 20’s at 3,500′.
Tuesday looks to be a short break in weather before a much warmer and wetter system moves in from the South for Wednesday. We could see rain above 2,000′ with this next round of storms mid-week.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||28||1||0.1||109|
|Summit Lake (1400′)||29||0||0||32|
|Alyeska Mid (1700′)||30||6||0.5||87|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||24||–||–||–|
|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: 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.