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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   Heather Thamm  
Thursday, March 10th 2016
Created: Mar 10th 5:58 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.
0 NO RATING Below Treeline / Below 1,000'
 Show the Complete North American Avalanche Danger Scale
Alaska Mountaineering and Hiking
Special Announcement

Tune-up your avalanche skills for Spring Break! Know Before You GO!

Tonight, March 10th we are offering a FREE Avalanche Awareness Class at the Girdwood Community Center from 6:30-8:00 pm. This is sponsored by Powderhound Ski Shop. For more info click HERE. Join CNFAIC avalanche specialist Heather Thamm for a great intro to avalanche education.

Saturday, March 12th join us at Turnagain Pass for a FREE Avalanche Rescue Workshop from 11 am-12:30 pm at the motorized lot on Turnagain Pass. This class is open to everyone. Please bring your beacon, shovel and probe. For more info click HERE. Look for the blue CNFAIC Avalanche trailer. We hope to see you all there!


The Bottom Line

The avalanche danger is MODERATE today above 1000’. Glide cracks continue to release naturally and without warning and threaten a lot of mid-elevation terrain. Indentify slopes with glide cracks and avoid being within the runout of a glide. General caution is advised for the alpine where wind slabs, loose snow, and large cornices should be factored into your decisions.

* Similar avalanche conditions exist in the Summit Lake area, but the snowpack is more complex and variable. Click HERE for a video and observation from yesterday that shows an addtional conern to be aware of. 


Primary Concern

Glide cracks continue to threaten large areas of terrain throughout Turnagain Pass, Girdwood, and Summit Lake. There were several new glide avalanches seen yesterday from the Seward Hwy, and a large glide released on the East face of Seattle Ridge a few days ago. Glide cracks are on all aspects within the mid-elevation band (1000'-2500'), and some areas like the SW face of Cornbiscuit and Tincan are covered. This avalanche problem is impossible to predict and is not associated with human triggers. We have been talking about the glide avalanche problem for over two months in the advisory and as long as glide cracks continue to open up, move and release, we will stress the importance of avoiding them. 

Yesterday a glide on the Southwest aspect of Orca released mid day. Click HERE is see more photos of glides that released in the last 2 days. 

 

Glides cracks on the SW face of Cornbiscuit as seen yesterday. Photo by Liz Rapetto. Click HERE for an observation that shows a portion of a glide (out of view) that partially released on Cornbiscuit.


Secondary Concern

In the alpine be on the lookout for a variety of surface snow instabilities and changing conditions later in the day.

Wind Slabs: Today as ridgetop winds start to increase by late afternoon be aware of newly forming wind slabs in steep terrain. Should you see blowing snow or shooting cracks consider altering your plans. This is the kind of hazard that might catch you off guard in the afternoon as conditions change.

Loose snow: On shaded aspects dry loose snow sluffing will warrant management in steep terrain.  Sluffs have been fast moving with the ability to entrain a significant amount of surface snow in big terrain. On solar aspects pay attention to how the sun is warming the surface snow. Triggering a wet loose avalanche may be possible if the sun is packing some heat today.

Cornice falls: Very large cornice features can be found along most ridgetops throughout Turnagain Pass. Cornices have a tendency to break further back than expected. Give them lots of space, and limit time under them. Should you get too close, a snowmachine or person could tip the balance. 

 

 


Mountain Weather

Yesterday skies were sunny and ridgetop winds were calm.  Daytime high temps reached the low 40’s F and overnight temps dipped down into the mid 20’s F. Ridgetop winds have increases slightly overnight from the East, averaging 10mph.

Today skies are expected to be mostly sunny becoming cloudy with scattered snow showers by early evening. Easterly ridgetop winds will continue to increase throughout the day and are expected to reach 15-30mph by early evening. Daytime temperatures will be in the 30’s F and may reach the low 40’s at lower elevations.

A weak low will move through the area Tonight through Friday bringing scattered showers with up to a few inches of new snow. Winds will be moderate from the East and temperatures will continue to be warm, upper 20’s -30’s F. 

 

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

  Temp Avg (F) Snow (in) Water (in) Snow Depth (in)
Center Ridge (1880') 32  133 
Summit Lake (1400') 29  43 
Alyeska Mid (1700') 33  106 

 

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

  Temp Avg (F) Wind Dir Wind Avg (mph) Wind Gust (mph)
Sunburst (3812') 26  ENE  17 
Seattle Ridge(2400') 29  SE  19 

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 28, 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: OpenPlacer remains open but SKOOKUM DRAINAGE will close to motorized use on April 1st.
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

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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.


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.
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