Avalanche Advisory

Turnagain Area Avalanche Advisory
Wednesday, November 29th 2017 4:24 am by Aleph Johnston-Bloom
ARCHIVED ADVISORY - All advisories expire after 24 hours from the posting date/time.
Previous ForecastNext Forecast
The Bottom Line

The avalanche danger is CONSIDERABLE. New snow, rain and sustained winds have loaded a weak snowpack. Triggering a slab 1 - 2+ feet thick is likely. Natural avalanches are possible. Cautious routefinding and conservative decision-making are essential today.  

*Below Treeline: ICE CLIMBERS in Portage Valley: Avalanches today could release naturally in higher terrain, sending debris over climbing routes. 

 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

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, December 5th @ 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.

The CNFAIC Events Calendar is filling up with avalanche education opportunities. Check it out and find a class that is right for you! 

*The forecasters want to send a shout out to the group practicing companion rescue on Tincan yesterday. Nice work! Great reminder for everyone to get out and practice with your crew!

**For Hatcher Pass avalanche conditions see

Avalanche Problem 1

New snow, rain and sustained winds overnight have elevated the avalanche danger. 8-10" of snow fell at upper elevations in Girdwood and 5-8" at Turnagain in the last 24 hrs. Winds were easterly 20-30 mph with gusts into the 50s.  Unfortunately some of the precipitation has fallen as... yuck, rain to around 1500', maybe a bit higher. It is 34F at the Center Ridge Snotel (1880') this morning. Yesterday the balance had not quite been tipped by new snow and wind loading but there was widespread cracking, whumpfing and a recent small natural avalanche observed (red flags). Hand pits showed failure on isolation between new snow and the underlying facets. This weak snow rests either on the ground or overlying a melt-freeze crust near the ground. With the additional snow and wind loading overnight this now sits below a more cohesive slab. Triggering a slab on steep terrain will be likely, especially in leeward, wind loaded areas. This snowpack set-up has the potential to be very touchy. Collapses (whumpfs) may propagate failure over large pieces of terrain and remote triggering an avalanche is possible. Don't let early season stoke lure you into a dangerous spot. Overall it is still fairly shallow and rocky, getting caught in an avalanche could take you for a very unpleasant ride. Rain falling on this snowpack will also add weight and break up bonds. Wet loose avalanches may run naturally at low elevations in steep channeled terrain. 

Quick snowpit at 1000' near large collapse. Weak facets below new snow. 

Cracking in snowpack near skin track, propagating across terrain. 


Mountain Weather

Yesterday was mostly overcast with light precipitation on and off throughout the day. Turnagain saw a few breaks in the clouds. Winds were easterly 10-20 during the day, ramping up overnight into the 30s with gusts into the 50s. Overnight snow picked up and rain fell to around 1500'. 8-10" of snow fell at upper elevations in Girdwood with .6-1" of SWE (snow water equivalent). Turnagain picked up 5-8" at .5 SWE. Temperatures were in the mid 30Fs to mid 20Fs depending on elevation. 

Today will be mostly cloudy with snow showers. These showers may be locally heavier at times due to unstable air behind the current front. An additional 1-5" of snow is forecasted to fall. Winds will be easterly 10-20 mph with gusts into the 30s. Rain/snowline is expected to drop as temperatures cool down in the afternoon/evening.  Temperatures will be in the mid 30Fs to mid 20Fs. Light snow showers may continue overnight. 

Thursday will be mostly to partly cloudy and cooler with a wind shift to the NW. Temperatures will be in the 20Fs dipping into the teens at night. There is a break in the stormy pattern on Friday before more unsettled weather moves in again over the weekend. 

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

  Temp Avg (F) Snow (in) Water (in) Snow Depth (in)
Center Ridge (1880')  34  6 .5  12 
Summit Lake (1400')  32  0  0
Alyeska Mid (1700')  32  8 .6  14


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

  Temp Avg (F) Wind Dir Wind Avg (mph) Wind Gust (mph)
Sunburst (3812')  23 ENE   28 56 
Seattle Ridge(2400')  26 rimed  rimed   rimed

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

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
© 2018 Chugach National Forest Avalanche Information Center. All rights reserved.