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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   Wendy Wagner  
Tuesday, January 1st 2013
Created: Dec 31st 12:47 pm
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.
4 High Below Treeline / Below 1,000' Travel Advice: Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
 Show the Complete North American Avalanche Danger Scale
The John Byrne Family
Special Announcement

The AK DOT will be conducting avalanche hazard reduction work today at 1100 on the Seward Highway near milepost 99. See 511.alaska.gov for more information.


The Bottom Line

BOTTOM LINE
A quick hitting storm over the Turnagain Pass region currently will keep our avalanche danger at HIGH today. Additional snow and wind will continue to stress the snowpack throughout the day and natural avalanches are likely. Human triggered avalanches will be very likely and it is recommended to steer clear of avalanche terrain today.


Primary Concern

Happy New Year! Well, the holiday season has not disappointed. In the past week we have more than doubled our snowpack and in some areas tripled it! But, the action is not over. We will welcome in 2013 with yet another storm. This one should be quick hitting but will add another couple feet to our deepening pack.

With current snowfall rates at 1-2 inches per hour this morning we can expect all the usual storm snow problems. These are:

Wind slabs – slab avalanches formed in areas where the winds are loading slopes.
Storm slabs  - slab avalanches in areas without wind that occur before the new snow has time to bond with itself.
Sluffing – loose snow avalanches on steep slopes where the new snow lacks cohesion.

The new slabs formed today will be around 1 1/2 to 2 ft deep and likely quite touchy. At elevations below 2500' there is a crust formed by the rain on snow from Dec 30th that will act as a bed surface under the new snow. Slides triggered at these lower elevations could run quite far. Getting tangled up in one of these could quickly ruin your day. Staying out of avalanche terrain is still your best bet for getting back to the car safely.


Secondary Concern

The above concerns are all issues dealing with the storm snow and the top layers of the snowapck - but we cannot forget about what is lurking below – the unmanageable and unsurvivable deep slab problem. We continue to have a VERY WEAK foundation to our snowpack and we saw quite a bit of evidence for this yesterday. A quick break in the clouds allowed a look at the recent avalanche activity around the Pass from the past several days. Unfortunately we were not able to see all the popular haunts but HERE is a run-down of what we were able to get a peek at.

Most of the avalanches seen the past week have failed in the weak snow at the bottom of the pack. The slab on top is still around 4-6' thick in most places and becoming more dense. The slab is also showing signs of getting harder to trigger which is setting us up for a tricky and deadly combination. Meaning, the likelihood of triggering is decreasing but if one of these pulls out, has the potential to be large and dangerous.


Mountain Weather

We have an intense and quick hitting storm over us this morning. Several weather stations in the Turnagain Pass area are not reporting, but looking at the Girdwood Valley and Alyeska stations we are seeing ridgetop winds in the 30-40mph range (these could easily be stronger around the pass). Temperatures are beginning to cool slightly from the upper 30’s at sea level to the mid 30’s and the upper 20’s on the ridges to the mid 20’s Fahrenheit. Precipitation has begun in earnest with 10” of snow as of 6am this morning. The rain/snow line is hovering at sea level where it should remain. We should see another 8-12” of snow through today. Snow showers should taper off later today.

 


Kevin will issue the next advisory on Wednesday morning, January 2nd.

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: Dec 08, 2017 )

AREA STATUS WEATHER AND RIDING CONDITIONS
Glacier District
Johnson Pass: Closed
Placer River: Closed
Skookum Drainage: Closed
Turnagain Pass: ClosedRain and snow have fallen in Turnagain Pass this week, but not enough to open for snowmachining. Continue to check back to this site for updates.
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
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