CNFAIC LogoCNFAIC Logo

Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   CNFAIC Staff  
Thursday, March 15th 2012
Created: Mar 15th 6:48 am
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.
 Show the Complete North American Avalanche Danger Scale
TOTE Maritime
The Bottom Line
Good morning. This is Chris Engelhardt with the Chugach National Forest Avalanche Information Center on Thursday, March 15th at 7am. This will serve as 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).

BOTTOM LINE

The avalanche danger is CONSIDERABLE throughout the region today. New snow soft slab avalanches, wind slabs and large loose snow avalanches are all a concern. Conservative route finding and decision making are essential. Human triggered avalanches are likely.


AVALANCHE DISCUSSION

Nearly 2 feet of new snow fell at or above tree line Tuesday night through the day Wednesday. The new snow was so deep that making turns was nearly impossible yesterday. The new snow was deposited fairly rapidly and was very reactive to sluffing and soft slabs on steeper aspects below tree line. We found easy fracture results with a compression test on a southwest aspect. Sure enough, the new storm snow was collapsing and failing on a sun crust, around 1.5-2 ft below the surface. The new snow also propagated easily across this sun crust layer on an extended column test. This crust is widespread on south and southwesterly aspects and proved to be a trigger point by yesterdays observations. Please check our Observations page. Loose snow sluffing was engulfing and significant on the small steeper north aspects that we ventured on. We also observed small natural point releases on the east side of Seattle ridge. After the dry and sunny weather last week, this storm snow fell on quite a variety of snow surfaces (sun crusts, facets, surface hoar, and smooth wind slab). This provides a wide difference of surfaces for the new snow to bond to. With this in mind, caution, good investigation, and fore thought is needed today for safe travel plans.

Concern #1 Storm Snow

There is a lot of new snow out there and has not had much time to settle yet. Moderate winds during and after the storm combined with the variety of snow surfaces it fell on are conditions that deserve respect and careful evaluation when looking for travel routes. Steep and open slopes or terrain exposed from above should be avoided.

Concern #2 Wind Slab

Terrain more exposed to wind will likely see stiffer and deeper slabs with a greater probability for avalanches. Avoiding all catchment areas, steep exposed terrain, corniced ridges, roll overs and everything where visibility is compromised would be wise. Wind loaded areas could have double the amount of deposited snow making for deeper much more dangerous conditions.


MOUNTAIN WEATHER

Girdwood valley residents awoke yesterday to a surprising amount of snow, (nearly a foot in some places). We found 14 on the road at Turnagain Pass and nearly 2 feet at tree line on Tincan at noon yesterday. Winds were moderate during the day and averaged in the 16-19mph range. Temps were warm in the high 20s.
Winds continued to be moderate overnight averaging in the low 20s from the east and temperatures averaged around 21F. Today we could see continued snowfall (possibly 3-6) along with cloudy conditions, moderate winds from the east at ridgetop and warmer temps, perhaps into the low 30s at around 1000ft elevation.


CNFAIC Weather Page and the NWS forecast

Kevin will issue the next advisory Friday morning. If you get out in the backcountry we want to know what you are seeing. Please send us your observations using the button at the top of this page or give us a call at 754-2369. Thanks and have a great day.

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: Nov 18, 2017 )

AREA STATUS WEATHER AND RIDING CONDITIONS
Glacier District
Johnson Pass: Closed
Placer River: Closed
Skookum Drainage: Closed
Turnagain Pass: ClosedOnly a few inches of snow sits at the motorized lot, not enough to open for snowmachining at this time. Updated Nov. 18, 2017
Twentymile: Closed
Seward District
Carter Lake: Closed
Lost Lake Trail: Closed
Primrose Trail: Closed
Resurrection Pass Trail: ClosedResurrection Pass trail is expected to open to snowmachine use during the 2017/18 winter season.
Snug Harbor: Closed
South Fork Snow River Corridor: Closed
Summit Lake: Closed

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