Avalanche Advisory

Turnagain Area Avalanche Advisory
Tuesday, December 5th 2017 4:16 am by Aleph Johnston-Bloom
ARCHIVED ADVISORY - All advisories expire after 24 hours from the posting date/time.
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The Bottom Line

The avalanche danger is CONSIDERABLE at all elevations today. Triggering a slab 2-3+ feet thick will be likely on slopes steeper than 30 degrees and natural avalanches are possible as the next storm system moves into the region. Cautious route-finding and conservative decision-making are essential today. Pay attention to changing conditions. If today's storm is more intense than forecasted the danger will bump back up to HIGH. 

Below 1,000' where predominantly rain is falling, debris running into these lower elevations from avalanches remains possible along with wet loose avalanches on steep slopes. 


 Show the Complete North American Avalanche Danger Scale
3 Considerable Alpine / Above 2,500' Travel Advice: Dangerous avalanche conditions. Careful snowpack evaluation, cautious routefinding and conservative decision-making essential.
3 Considerable Treeline / 1,000'-2,500' Travel Advice: Dangerous avalanche conditions. Careful snowpack evaluation, cautious routefinding and conservative decision-making essential.
3 Considerable Below Treeline / Below 1,000' Travel Advice: Dangerous avalanche conditions. Careful snowpack evaluation, cautious routefinding and conservative decision-making essential.
Special Announcement

**Increased avalanche conditions have been seen across Southcentral, Alaska. This includes an Avalanche Warning issued through the NWS for High Avalanche Danger at Hatcher Pass, see updated forecast at

Motorized use on Turnagain Pass is closed due to insufficient snow cover.  Please see riding area status at the bottom of this page for the most up-to-date information.


Snowmachine Specific – Avalanche Safety and Lessons Learned at AMDS, 6:30 pm - 8:00 pm | FREE Join CNFAIC forecasters at Alaska Mining and Diving Supply for a talk about lessons learned from past avalanche events and get your brain in gear for avalanche season.


Know Before You Go - Avalanche Awareness at the Seward Community Library, December 8th, 1 pm - 4 pm | FREE Join CNFAIC for a great intro to avalanche recognition and rescue, including hands-on beacon practice.


Avalanche Problem 1

The advisory area continues to be in an unsettled weather pattern. Snowfall, rain and wind will continue to add stress to the snowpack. Yesterday was a lull in intensity after 2-3' of snow (2-3" of rain at sea level) fell and winds gusted over 100mph on Saturday. There was evidence of an avalanche cycle during the storm observed yesterday. This was not quite as widespread as expected which leaves many slopes suspect and human triggered avalanches likely and additional natural avalanches possible. An example illustrating this point is that avalanche hazard mitigation in the Girdwood Valley yesterday produced avalanches running to ground on slopes adjacent to natural avalanches that had run in the storm. Translation: slopes that haven't slid could be hanging in the balance waiting for a trigger. Don't be that trigger. It might not be the 1st person on the slope. The slab depth has increased over the weak faceted snow. Remember the facets were very reactive prior to the storm. Staying off of slopes steeper than 30 degrees and avoiding runout zones will be important today. A small slide into a terrain trap could be consequential.  Additional snow and rain are forecasted to fall and winds could move snow at upper elevations increasing the load today.  This snowpack will need time to adjust. Be patient and be on the lookout for recent avalanches, cracking and collapsing, signs that the snowpack unstable. 

Natural avalanches on Sunburst that occurred during the storm Saturday.


Small avalanches and wind effect in along Seattle Ridge. 


Avalanche Problem 2

Very high winds during the storm Saturday have loaded leeward slopes. In addition there is snow falling today and winds gusting into the 40s. Winds slabs are likely found along ridgelines as well as lower down slopes due to those high wind speeds on Saturday. Pay attention to cracking and hollow sounding snow. Wind slabs could be soft or hard depending on exposure to winds and if triggered could release a larger persistent slab lower down on the slope. Today is not the time to be pushing into steep terrain. Avoiding slopes greater than 30 degrees is recommended.

Wind loading on leeward slopes, Tincan.

Mountain Weather

Yesterday was overcast with light rain and snow showers on and off throughout the day. Winds were easterly 15-25 mph with gusts as high as 60 mph. Upper elevations picked up an additional 2-5" of snow and rain fell to around 1500'. Temperatures were as high as 40F at sea level and the mid to high 20s at upper elevations. 

Today will be mostly cloudy with .4" of water (4-6" snow) forecasted to fall. Today will start warmer and cool a bit this morning bringing the snow level down. Winds will be easterly 10-20 mph gusting into the 40s.Tonight into tomorrow a stronger wave of precipitation is forecasted to impact the area. The model runs on this are still uncertain this morning, however looking into the future NWS says "Much more confidence exists in the forecast for Southcentral to remain well above normal for temperatures, and continue to deal with round after round of moisture from the subtropical Pacific. Stay tuned! 

*Center Ridge SNOTEL is reporting erroneous temperature data. See Turnagain Pass DOT weather station for accurate temperature at 1000'.

 PRECIPITATION 24-hour data (6am - 6am)

  Temp Avg (F) Snow (in) Water (in) Snow Depth (in)
Center Ridge (1880') 32*   0  .2 29 
Summit Lake (1400') 33   0  .3  9
Alyeska Mid (1700') 34   0  .2  18


RIDGETOP 24-hour data (6am - 6am)

  Temp Avg (F) Wind Dir Wind Avg (mph) Wind Gust (mph)
Sunburst (3812')  24  ENE  26 60 
Seattle Ridge(2400')  28  ESE   18 40

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: Mar 15, 2018 )

Glacier District
Johnson Pass: Open
Placer River: OpenPlease avoid private property and AKRR job site at Luebner Lake. Cross railroad tracks if needed, do not ride down tracks, it is illegal.
Skookum Drainage: OpenCross railroad tracks if needed, do not ride down tracks, it is illegal. FYI, Skookum drainage closes to Snowmachines on 4/1 as per the Chugach NF plan.
Turnagain Pass: Open
Twentymile: OpenCross railroad tracks at designated spot as you leave the parking area.
Seward District
Carter Lake: Open
Lost Lake Trail: Open
Primrose Trail: Open
Resurrection Pass Trail: OpenResurrection Pass trail is open to snowmachine use during the 2017/18 winter season.
Snug Harbor: Open
South Fork Snow River Corridor: Open
Summit Lake: Open

Subscribe to the Turnagain Area Avalanche Advisory:

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.

If you have comments or questions regarding CNFAIC operations or winter recreation management, please email
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