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Avalanche Advisory

Turnagain Area Avalanche Advisory
Monday, December 19th 2011 6:58 am by Wendy Wagner
ARCHIVED ADVISORY - All advisories expire after 24 hours from the posting date/time.
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BROUGHT TO YOU BY
The Bottom Line
Good morning. This is Wendy Wangner with the Chugach National Forest Avalanche Information Center on Monday, December 19th 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).

ANNOUNCEMNTS
There will no advisory issued tomorrow, Tuesday. The next advisory will be issued Wednesday, December 21st, at 7am. See Tuesday's outlook below.

BOTTOM LINE
There is a CONSIDERABLE avalanche danger today for unmanageable soft slab and wind slab avalanches formed in yesterdays 2+ feet of new snow. This means human triggered avalanches are likely and will be deep and dangerous if released. Most probable areas to avalanche are steep slopes near and above treeline. The snowpack is currently adjusting to yesterday's rapid load and needs time to bond.

AVALANCHE DISCUSSION
AnCNFAIC Staff rapidly intensifying storm rolled through our region yesterday. In a roughly 12 hour span, 2 feet of snow fell in the Turnagain Pass area, with a bit more in the Girdwood Valley and less in the Summit Lake area. Gale force easterly winds accompanied the snow and an ensuing natural avalanche cycle was seen/reported in the Girdwood area. The poor visibility kept observations limited as to the extent of CNFAIC Staff natural activity.

Human triggered soft slab and wind slab avalanches will be the primary concerns. These are likely to be unmanageable with the amount of new snow that fell yesterday. Avoiding steep slopes today is advised as it has only been 24hours since the storm and we do not know exactly how the pack is reacting. The decreasing temperatures today will help to lock things in place, but do not count on it yet. Wind deposited areas are likely to be deep and soft and cornices large and sensitive. Cornices will deserve a wide berth. Expert level route-finding skills and terrain management will be required in the backcountry today.

Tuesdays Outlook
Tuesday, the avalanche concerns will be similar to Monday with a decreasing trend in danger as the snowpack heals. However, any new snow and wind Monday night will increase the danger for new snow instabilities.

MOUNTAIN WEATHER
Yesterdays quick and dirty storm laid down anCNFAIC Staff good shot snow in most locations. Turnagain Pass saw 2, mid-elevations in the Girdwood Valley 2 ' with Summit Lake around 1 at 1400. The last two weekend storms have doubled the Turnagain Pass overall snow depth. Easterly winds again tore through the region with 50-60mph hourly averages and over 100mph gusts. The sunburst wind sensor finally died after reporting a 104mph gust. The storm decreased significantly in the afternoon and overnight winds and have been moderate from the south, with stronger southerly gusts in the Summit area. Temperatures have decreased as well and are currently around 30F at sea level, mid 20s around treeline and 20F on the ridges.

Today, partly to mostly cloudy skies will fill back in with a pulse of weather moving through later in the day. Light to moderate SW winds will turn SE with a chance for a couple of inches of snow tonight.

Tuesday, the weather looks to pick up in the afternoon with increased wind, and possibly snow, ahead of anCNFAIC Staff system moving in on Wednesday.


CNFAIC Weather Page and the NWS forecast

Kevin will issue the next advisory Wednesday 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.

 Show the Complete North American Avalanche Danger Scale
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.

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: May 06, 2018 )

AREA STATUS WEATHER AND RIDING CONDITIONS
Glacier District
Johnson Pass: ClosedClosed as of April 20th
Placer River: ClosedClosed as of April 17th
Skookum Drainage: ClosedClosed as of April 1st.
Turnagain Pass: ClosedClosed as of May 7th. Happy summer, see ya when the snow flies!
Twentymile: ClosedClosed as of April 13th
Seward District
Carter Lake: ClosedClosed as of 4/27
Lost Lake Trail: ClosedClosed as of April 13th
Primrose Trail: ClosedClosed as of April 13th
Resurrection Pass Trail: ClosedClosed as of April 20th
Snug Harbor: ClosedClosed as of 4/27
South Fork Snow River Corridor: ClosedClosed as of April 13th
Summit Lake: ClosedClosed as of April 20th

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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