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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   Wendy Wagner  
Friday, November 27th 2015
Created: Nov 27th 6:23 am
4 High Alpine / Above 2,500' Travel Advice: Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
4 High Treeline / 1,000'-2,500' Travel Advice: Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
2 Moderate Below Treeline / Below 1,000' Travel Advice: Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
 Show the Complete North American Avalanche Danger Scale
The Hoarding Marmot
Special Announcement

WARNING:

DANGEROUS AVALANCHE CONDITIONS REMAIN IN MANY AREAS both South and North of Anchorage.

This includes Hatcher Pass where a HIGH Avalanche Danger exists - see hatcherpassavalanchecenter.org.

The Hatcher Pass road closure is still in effect and Park Rangers are recommending the public avoid this area. Also, there remains a missing skier at Hatcher Pass. In addition to the road being closed, please be respectful of the rescue efforts.

Petersville / Cantwell areas:

Large avalanches have been reported North of Talkeetna and Cantwell. Although excitement is high for Thanksgiving Powder, PLEASE be extra conservative when choosing your backcountry location. There is plenty of mellow terrain to play in but please avoid avalanche terrain - any slope over 30 degrees and its runout! 


The Bottom Line

For the Turnagain Pass, Girdwood and Summit Lake (Kenai) regions a HIGH avalanche danger remains. Another storm moved through overnight adding 12-18" of heavy snow at the upper elevations and rain below 2,500'. This, accompanied by winds gusting to 109mph, will continue to destabilize the snowpack. 

Natural and human triggered avalanches are likely. MODERATE danger exists below 1,000' in snow-free gullies and runouts where debris can be channeled from an avalanche above; possibly affecting hiking trails (see photo below).

Travel in avalanche terrain is NOT recommended again today. The good news is, snow is piling up in the mountains - at the upper elevations. With little detailed information at this time, we are asking folks to be patient and conservative in the backcountry until these storm cycles cease.


Primary Concern

For anyone looking at the weather stations this morning, you may have had the same reaction I did - Nooo, rain over 2,000'! A sinking reminder of last season. The storm system that rolled in last night is entraining warm subtropical air, more than forecast.

Considering this round of rain-on-snow affecting higher and drier snowpacks, we should see additional wet avalanche activity today. Many of these slides are confined to very steep terrain (pictured below), however we did have a report of a large full depth avalanche on the SW face of Max's Mtn in Girdwood. We do not have a photo of the Max's slide yet, but this is a popular ski/snowboard area.


Photos below: Debris reaching close to sea level in a slide path just South of Girdwood (left) and paths across the Arm (right). An example of how avalanches can affect snow-free zones.
  

 

*Snow conditions at Turnagain Pass yesterday were less than ideal for skiing/snowboarding; very wet and heavy unsupportable snow transitioned to moist and 'punchy' snow above treeline. Remember, snowmachining is still closed due to insufficient snow at the parking lot. 


Secondary Concern

At the upper elevations it is snowing and blowing. The Sunburst anemometer (wind sensor) had a max gust of 109mph at 6:00 this morning!! Snowfall amounts are roughly 12-18", with higher amounts in favored locations such as Girdwood and Portage Valleys. The snow cover is filling in up high with sticky Chugach Powder, which is great news. But, patience is warranted until the pack can adjust. 

We saw very little natural avalanche activity from the Thanksgiving storm that deposited 14-16" above treeline. However, we are still concerned we could see large 'connected' avalanches due to a layer of faceted snow at the base of the pack (formed during the cold snap). This layer is not uniform and only exists in scattered zones (Todd's Bowl is a suspect). With a new load added today, we will be looking for not only avalanches but the character of them.

Photo below: Tincan Common Bowl is filling in (top of bowl is around 3,200')


Additional Concern

A number of glide cracks exist at mid-elevations on Turnagain pass, notably in areas such as the Tincan trees. Glide avalanches are very unpredictable and the recent warming temperatures and rain could cause a glide crack to release. Hence, travel under glide cracks should be limited.


Mountain Weather

As you can see in the charts below, well over an inch of rain fell at the mid-elevation snow stations last night. This storm system is expected to continue through today with another 1" of rain below ~2,000' and 10+" of snow at the upper elevations. Winds will remain Easterly with averages in the 30's to 40's mph. Temperatures should drop slightly today by a few degrees.

For the weekend, instability showers will be over us with a slightly lower rain/snow line. Skies may clear a bit as well for the weekend and the Easterly winds decrease. Stay tuned. 

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

  Temp Avg (F) Snow (in) Water (in) Snow Depth (in)
Center Ridge (1880') 34  0 (rain overnight)  1.4  25 
Summit Lake (1400') 36  0 (rain overnight)  0.5 10 
Alyeska Mid (1700') 34  0 (rain overnight)  1.6  18 

 

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

  Temp Avg (F) Wind Dir Wind Avg (mph) Wind Gust (mph)
Sunburst (3812') 27  ENE  42  109 
Seattle Ridge(2400') 29   SE   33  72 

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: Jan 18, 2017 )

AREA STATUS WEATHER AND RIDING CONDITIONS
Glacier District
Johnson Pass: OpenAccess is thru the gate on the right side of the parking lot as you drive toward the outhouse. Please park on road in and leave the turnaround (near outhouse) open for trailers to turn around.
Placer River: OpenPlease cross Railroad tracks at 90 degrees to the rails and clear the corridor. It is Illegal to ride up and down Railroad tracks. Tracks are currently active. Please observe and stay off PRIVATE PROPERTY adjacent to the Portage Valley.
Skookum Drainage: Open
Turnagain Pass: Open
Twentymile: OpenPark at Portage rail depot. Cross tracks and follow marked corridor (Bamboo poles) approx. 3 miles up Valley to open riding areas.
Seward District
Carter Lake: Open
Lost Lake Trail: OpenOpen to motorized use 1/15. Please STAY ON existing and hardened trail surface through the lower sections of this route.
Primrose Trail: OpenOpen to motorized use 1/15. Please 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
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