Monday, December 3rd 2018 7:00 am by Aleph Johnston-Bloom
ARCHIVED ADVISORY - All advisories expire after 24 hours from the posting date/time.
The avalanche danger is MODERATE above 2500’ in the Alpine. Human triggered slab avalanches up to 1-3’ thick remain possible due to a weak layer of snow under the Thanksgiving weekend storm snow. Additionally, watch for lingering wind slabs in steep wind-loaded terrain.
|Show the Complete North American Avalanche Danger Scale|
|Travel Advice: Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.|
|Travel Advice: Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.|
New snow and wind has increased avalanche conditions in many zones outside of the Chugach National Forest.
- If you are heading to Hatcher Pass make sure to check out the Hatcher Pass Avalanche Center's forecast and the latest observations.
- Reports also sent into us from Anchorage's Front Range - see those HERE .
In the Alpine, sitting anywhere from 1 to 3' below the snow surface, is a thin layer of weak snow (buried surface hoar/BSH). An observer yesterday found this layer to still be reactive in a snowpit on Sunburst right around 2500'. This buried weak layer remains a concern. At this point obvious signs of instability may not be observed but the possibility of triggering an avalanche cannot be ruled out. As always use safe travel protocol and choose terrain with consequences in mind i.e. where is the avalanche path and where would I end up if the slope slides? The snowpack profile below illustrates the slab sitting over the weak layer.
Snowpit on Sunburst, December 2, 2018. Observer: Chris Robertson
Snow cover looking south on Turnagain Pass, December 2, 2018. Photo: Allen Dahl
Be on the lookout for wind slabs in steep unsupported terrain. Strong easterly winds on Saturday afternoon may have loaded leeward slopes in the Alpine. It may still be possible to trigger a lingering pocket that could be dangerous. Look for stiff, pillowed snow and cracking and listen for hollow, drum-like sounds.
Yesterday: Skies were overcast and there were very light rain/snow showers. Temperatures were in the mid 30Fs to mid 20Fs. Winds were easterly 10-20 mph with gusts into the 30s.
Today: Cloudy skies in the morning becoming partly sunny. Temperatures will be cooling from the 30Fs into the lower 20Fs as skies clear and colder air moves over the region. Winds will be northeasterly 5-15 mph with gusts into the 20s. Expect overnight temperatures in the low 20Fs and high teens. Clouds will move back in overnight.
Tomorrow: Chance of snow showers and increased easterly winds in the afternoon as the next front moves over the area. The pattern remains active through the week. As usual the temperatures and timing are uncertain. Stay tuned!
*Seattle Ridge wind sensor is rimed over.
PRECIPITATION 24-hour data (6am - 6am)
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880')||33||1||0.1||13|
|Summit Lake (1400')||29||3||0.3||2|
|Alyeska Mid (1700')||33||0||0.19||N/A|
RIDGETOP 24-hour data (6am - 6am)
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge(2400')||29||*no data||*no data||*no data|
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).
Riding status is not associated with avalanche danger. An area will be open to motorized use in accordance to the Forest Management Plan when snow coverage is adequate to protect underlying vegetation. Backcountry hazards including avalanche hazard are always present regardless of the open status of motorized use areas.
(Updated: Mar 22, 2019 )
|AREA||STATUS||WEATHER AND RIDING CONDITIONS|
|Placer River:||Closed||Closed as of 3.20.19 due to lack of snow.|
|Skookum Drainage:||Closed||Placer access closed as of 3.20.19 due to lack of snow.|
|Twentymile:||Closed||Closed as of 3.20.19 due to lack of snow.|
|Lost Lake Trail:||Closed||Closed as of 3/22. Unfortunately HEAVY rain over the past week has washed much of the snow off the lower stretches of this trail.|
|Primrose Trail:||Open||Please stay on trail to avoid resource damage through forested areas.|
|Resurrection Pass Trail:||Closed||Closed for the 2018/19 season. Next season will be open to motorized use.|
|South Fork Snow River Corridor:||Closed||Closed as of 3.20.19 due to lack of snow.|
SNOW AND AVALANCHE HOTLINE (907) 754-2369
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© 2019 Chugach National Forest Avalanche Information Center. All rights reserved.