CNFAIC LogoCNFAIC Logo

Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   Wendy Wagner  
Monday, January 25th 2016
Created: Jan 25th 6:25 am
2 Moderate Alpine / Above 2,500' Travel Advice: Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
2 Moderate Treeline / 1,000'-2,500' Travel Advice: Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
1 Low Below Treeline / Below 1,000' Travel Advice: Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
 Show the Complete North American Avalanche Danger Scale
Special Announcement

We are sad to report that as of yesterday the US has seen 9 fatalities in the past 9 days. One of these was the last fatality at Hatcher Pass (Hatcher Pass has seen 3 this season). You can view these reports at avalanche.org

  • Don't forget about tonight - Monday, January 25th, 7-8 pm: Come to the Blue and Gold Board Shop for a FREE Avalanche Awareness class taught by CNFAIC forecaster Heather Thamm. For more details click here: HERE. 

The Bottom Line

A MODERATE avalanche danger exists today above 1,000' in the mountains around Turnagain Pass. At elevations above 2,500' fresh wind slab avalanches ~6-12" thick will be possible to trigger on steep wind loaded slopes. Below 2,500', a MODERATE danger exists for glide cracks that may release spontaneously and avalanche. More details on these in the discussion below.

**If snowfall intensifies today adding more than 6" in the area you are recreating in, the avalanche danger will trend toward CONSIDERABLE where natural avalanche will be possible and human triggered wind slabs could be likely.


Primary Concern

A lot of people are wondering if the earthquake shook loose any avalanches yesterday? Well, the answer is yes, but not anything too big or bad or ugly - that we know of. With ok visibility yesterday, it looked as though several chunks of cornice fell and some of these triggered small wind slab pockets below them.

Below is a photo from South facing Magnum Ridge:

 

Check out the many observations sent in to us yesterday - many of these were from the Alaska Avalanche School's Level 2 course - thanks!

 

Avalanche concerns for today at the higher elevations (above 2,500' where it is snowing) will focus on the new snow and wind. We have seen another 4-6" of snow along with strong Easterly ridgetop winds overnight; this is on top of the 6" from Saturday night. Today we are expecting an additional 2-6" of snow with the moderate to strong winds remaining. Yesterday, wind slabs were stabilizing rapidly due to the warm temperatures and 'sticky' nature of the snow. We are expecting similar conditions for today. What to look for if visibility allows for travel above treeline:

  • How the winds have drifted the new snow from overnight and what sections of the slopes are loaded
  • Watching for shooting cracks
  • Jumping on wind loaded test slopes 
  • Quick hand and pole pits to see how any new slab is shearing 
  • Feeling for stiffer snow over softer snow


If you find cracking or any signs pointing to sensitive wind slabs steer clear of that slope. These slabs are sitting on a generally stable snowpack and not expected to step down into any deeper layers in the pack.

**However, shallow zones such as the Summit Lake area and South of Turnagain Pass harbor a variety of old weak layers in the pack. These have been mostly unreactive but something to keep in mind if a new load is placed on them. See the Summit Lake Summary from Saturday for more on this.

Although cornices got a good shake early yesterday morning, give these a wide berth as they could still be prime to fall.


Secondary Concern

Glide cracks continue to open and widen, yet we did not see any new releases yesterday. See video below from Corn Biscuit ridge (we were almost sure this thing was going to avalanche while we were up there...). As we keep mentioning, limiting time, or avoiding time altogether, under these things is highly recommended!

 

 

Closeup of a portion of the Corn Biscuit glide crack.


Mountain Weather

Obscured skies along with pockets of blue holes covered the area yesterday. Winds were in the moderate range on the ridgetops, 15-20mph from the East. Intermittent light snowfall (rain below 1,000') was seen with no accumulation.

Overnight, another warm and wet front has moved over us associated with a large low-pressure in the Gulf. Precipitation started falling around 9pm and as of 6am this morning, .5" of rain has fallen below 1,500' with 5" of dense snow above treeline. The Easterly ridgetop winds have jumped as well, these are blowing in the 30's mph with gusts in the 60's. Temperatures are in the mid 30's at 1,000' and the mid 20's F at 4,000'.

Today we should see cloudy skies with continued snowfall adding 2-6" of dense snow above 2,000' and ~.25-.5" of rain below 1,800'. Ridgetop winds are slated to remain in the 20-30mph range from the East with stronger gusts and temperatures will stay warm...(mid 30's F at 1,000' and mid 20's F on the ridgetops). Keep in mind with this weather pattern it will be possible to see more snowfall than predicted.

Tuesday, a break between systems will bring intermittent snow showers with some possible sunny breaks. Stay tuned.

 

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

  Temp Avg (F) Snow (in) Water (in) Snow Depth (in)
Center Ridge (1880') 32   0.5 90 
Summit Lake (1400') 35   0.1 27 
Alyeska Mid (1700') 33   .6 74 

 

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

  Temp Avg (F) Wind Dir Wind Avg (mph) Wind Gust (mph)
Sunburst (3812') 25  ENE  24 62 
Seattle Ridge(2400') 27  N/A   N/A  N/A  

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, 2017 )

AREA STATUS WEATHER AND RIDING CONDITIONS
Glacier District
Johnson Pass: OpenPlease park on road in and leave the turnaround (near outhouse) open for trailers to turn around.
Placer River: Open
Skookum Drainage: OpenSkookum drainage closes to motorized use on April 1 annually as per the Chugach National Forest Plan document.
Turnagain Pass: Open
Twentymile: Open
Seward District
Carter Lake: Open
Lost Lake Trail: OpenPlease STAY ON existing and hardened trail surface through the lower sections of this route.
Primrose Trail: OpenPlease STAY ON existing and hardened trail surface through the lower sections of this route.
Resurrection Pass Trail: ClosedClosed for 2016/17 winter season. This is a non-motorized season. This alternates every other year and will open again during the 2017/18 winter.
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.


USFS SNOW AND AVALANCHE HOTLINE (907) 754-2369
If you have comments or questions regarding CNFAIC operations or winter recreation management, please email staff@chugachavalanche.org
© 2017 Chugach National Forest Avalanche Information Center. All rights reserved.
FCNFAIC