Avalanche Advisory

Turnagain Area Avalanche Advisory
Friday, December 21st 2012 6:51 am by Wendy Wagner
ARCHIVED ADVISORY - All advisories expire after 24 hours from the posting date/time.
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The Bottom Line

A MODERATE danger continues today above treeline on previously wind loaded slopes steeper than 35 degrees where the possibility still remains for a person to trigger a slab avalanche. The most likely places to find and release one of these old persistent slabs are on slopes harboring stiff and hollow feeling snow - supportable to a person or snowmachine. Below treeline and areas above treeline where these stiff old slabs do not exist there is a LOW danger.

 Show the Complete North American Avalanche Danger Scale
2 Moderate Alpine / Above 2,500' Travel Advice: Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
1 Low Treeline / 1,000'-2,500' Travel Advice: Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
1 Low Below Treeline / Below 1,000' Travel Advice: Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
Avalanche Problem 1

As the Mayan Calendar predicted the end of the world at 2:11 this morning and along with that the end of our meager early season, it seems neither has occurred. The world is still here and so is our shallow snowpack full of persistent weak layers.

The wind slabs that caused so much excitement a week ago have been slowly deteriorating under the cold and clear weather to the point of becoming mostly non-reactive. Snowpack evaluations and the lack of recent avalanches have pointed to a pack that is becoming harder and harder to trigger an avalanche in. However, this is not the case everywhere and we struck gold, as John Fitzgerald stated in his observation, yesterday with finding one of these slopes still flashing red lights.

The areas we are most concerned about are in steeper, unsupported terrain (i.e., above cliffs and on rollovers at the mid-elevations) where stiffer, supportable snow (old wind slabs) are sitting on weak sugary snow. Watching and listening for collapsing and hollow feeling areas will be your best bet at sussing out suspect slopes. If you can punch a pole or boot though the stiff snow, though this may be tough in thicker slabs, and feel unconsolidated snow beneath – steer clear and head for a slope lacking that stiff slab.

Mountain Weather

The SEVERE CLEAR weather conditions will continue to dominate for another couple days. The strong inversion has temperatures at sea level and in the parking lots at Turnagain Pass near -20F. The good news is the temps have jumped to the balmy mid-teens on the ridgetops this morning, where they should remain. Winds have backed to an easterly direction overnight and will pick up to the 10-15mph range, gusting to 30mph, today.

The well entrenched, and not so loved, ridge of high pressure looks to start breaking down near the end of the weekend. Models are hinting at a little precipitation around Monday with a weak low pressure system developing the in Gulf. However, mid-week next week a larger low pressure moving into the Bering will hopefully bring a decent shot of precipitation – though this is too far out to say for certain…

Happy winter solstice!  A little comparison with last year’s solstice:  (Turnagain Pass SNOTEL, 1880')

                                            Dec 21, 2012                        Dec 21, 2011
Snow depth                              25”                                         78”
Seasonal snowfall                35”                                         129”
Seasonal water                      3.4”                                        13.4”

Roughly a quarter of where we were last season at this time – oh grim.


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). 

Kevin will issue the next advisory Saturday morning, December 22nd.

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).

Winter snowmachine use open/closed status and riding conditions updates

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: May 06, 2018 )

Glacier District
Johnson Pass: ClosedClosed as of April 20th
Placer River: ClosedClosed as of April 17th
Skookum Drainage: ClosedClosed as of April 1st.
Turnagain Pass: ClosedClosed as of May 7th. Happy summer, see ya when the snow flies!
Twentymile: ClosedClosed as of April 13th
Seward District
Carter Lake: ClosedClosed as of 4/27
Lost Lake Trail: ClosedClosed as of April 13th
Primrose Trail: ClosedClosed as of April 13th
Resurrection Pass Trail: ClosedClosed as of April 20th
Snug Harbor: ClosedClosed as of 4/27
South Fork Snow River Corridor: ClosedClosed as of April 13th
Summit Lake: ClosedClosed as of April 20th

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The information in this advisory is from the U.S. Forest Service, which is solely responsible for its content. This advisory describes general avalanche conditions and local variations always occur. This advisory provided by the Chugach National Forest, in partnership with Friends of the Chugach National Forest Avalanche Information Center.

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