Yesterday there was evidence of the winds moving Monday’s snow around across the region. Scouring, anti-tracks and drifting were observed, especially along upper elevation ridges. A few small natural winds slabs from right after the storm were observed with the crowns mostly filled in. There were no reports of human triggered winds slab avalanches in the advisory area but there was wind slab triggered in Summit Lake by a party skinning on the Tenderfoot ridge and a snowmachine triggered wind slab in Lost Lake. Northwest winds picked up in the evening and are forecast to remain strong throughout the day today. There is still some snow available for transport. Expect loading and slabs along ridgelines and look for pillowed or drifted snow. Northerly winds can funnel though Turnagain Pass from the South (especially at lower elevations) and there maybe loading on multiple aspects. Watch for shooting cracks and areas with stiffer snow. Steep, unsupported slopes that are loaded will be the most suspect. Slabs may be stiffer and harder to trigger today. They may be initially supportable and then fail above once out onto the slab. Look for blowing snow and pay attention to changing conditions.
Loose snow avalanches (sluffs): On steep slopes protected from the wind expect the new snow to sluff easily. These loose snow avalanches may be fast running and entrain snow quickly.
Sunshine: Remember that it is that time of year when we need to pay attention to the sun. The sun can heat up Southerly aspects, and melt surface snow and cause small point releases in the loose new snow. This will be more of a concern if winds become calm this afternoon. This heating can also cause a slab sitting on a weak layer to become more reactive. Avoid steep solar aspect if you notice the surface snow becoming moist or you see roller balls or point releases under rocks.
Wind effect on Eddies
Skier triggered sluff on Seattle Ridge
Snowmachine triggered wInd slab Lost Lake.
The overall snowpack structure across the advisory area is poor and it is important to keep in mind that larger slides breaking in persistent weak layers could still occur. The new snow load Monday, combined with the winds over the past two days, has added to the overall weight/stress from the small storms last week. This incremental loading can slowly overload weak layers making them more prone to triggering. Furthermore, avalanches triggered in the upper layers of the snowpack, like a fresh wind slab, have the potential to step down to the buried weak layers. In the upper elevations a layer of buried surface hoar from Jan. 21st continues to show signs of reactivity and in the mid-elevations a layer of facets over a melt-freeze crust is suspect. Observers on Tincan noted finding both layers Monday in their snowpits.
Deep Persistent Slabs: At the high elevations above 3,000′, deeper persistent layers could ‘wake up’ if the wrong spot is found. Old weak layers of facets and buried surface hoar sit in the bottom half of the snowpack. This structure is most pronounced in places with a thin overall snow cover, such as the South end of Turnagain Pass, the Summit Lake area and Crow Pass.
Yesterday was partly cloudy. Temperatures at upper elevations were in the single digits while the valleys were in the teens to low 20Fs. Winds shifted in the morning from SW to NW. Winds were light to moderate during the day and picked up in the evening gusting into the 60s on Seattle Ridge. Skies cleared overnight.
Today will be sunny and temperatures will be in the single digits at upper elevations and 20Fs at lower elevations. Winds will continue from the NW 20-30 mph gusting into the 40s during the day. They are forecast to slowly diminish overnight and into tomorrow.
Sunshine continues Thursday with slightly warmer temperatures and light winds. Clouds move in on Friday and there is a chance of snow over the weekend and into next week. Stay tuned for details!
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||20||0||0||73|
|Summit Lake (1400′)||11||0||0||30|
|Alyeska Mid (1700′)||12||0||0||65|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||8||NW||25||66|
|12/10/19||Turnagain||Avalanche: Tincan and Sunburst from the air||CNFAIC Staff|
|12/10/19||Turnagain||Observation: Tincan||Nancy Pfeiffer|
|12/08/19||Turnagain||Avalanche: Tincan||Ryan Van Luit Forecaster|
|12/06/19||Turnagain||Avalanche: Sunburst||Billy Finley|
|12/04/19||Turnagain||Observation: Sunburst||A.Johnston-Bloom/ W.Wagner/ R.Van Luit Forecaster|
|12/03/19||Turnagain||Observation: Hippy Bowl||Nick Langowski|
|12/01/19||Turnagain||Observation: Tincan, All elevations||Eric Roberts|
|12/01/19||Turnagain||Observation: Tincan||Andy Moderow|
|11/30/19||Turnagain||Observation: Tincan Treeline Plateau/ Common Bowl/ Ridge||Eric Roberts|
|11/29/19||Turnagain||Observation: Sunburst Ob #2||Aleph Johnston-Bloom 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|
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