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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   Kevin Wright  
Thursday, January 23rd 2014
Created: Jan 23rd 6:32 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.
4 High Below Treeline / Below 1,000' Travel Advice: Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
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The Bottom Line

Rain...

The unusually warm and long lasting rain event continues today.  Dangerous avalanche conditions are the new normal until this storm system ceases and temperatures get below freezing.  Specific areas may reach HIGH avalanche danger during periods of intense precipitation.  

Natural avalanches are happening periodically during this continuing storm cycle.  Some of these are quite large.  


Primary Concern

We continue to see new wet avalanche activity.  The big new one was on the west face of Cornbiscuit.  The lower part of the upper face pulled out full depth sometime between Tuesday night and Wednesday morning.  This area is above treeline but well within the zone that is getting rain.  See photo below.

As long as temperatures remain above freezing and especially during active rainfall, wet slab avalanches are possible and can be quite dangerous.  


Secondary Concern

Deep slab continues to be a concern as the upper elevations have stress added.  The equation here is simple - known reactive weak layers are getting heavy additional loading day after day.  These weak layers can cause large widespread avalanches anywhere from 4-7 feet deep and pull all the snow to the ground.  This problem is also worse during periods of precipitation, but will linger even after the storm ends.

Steep upper elevation terrain should be avoided, especially during periods of intense precipitation.  


Additional Concern

Up in the higher elevations there is enough storm snow and wind loading to have problems in the recent layers.  Think about wind slabs and storm slabs 1-3 feet in depth.  If an avalanche is started in these layers it could possibly step down into deeper layers.  I will be surprised if anybody actually makes it above the rain line today.


Mountain Weather

A steady jet of moisture is coming from subtropical latitudes, straight north to southcentral Alaska.  This pattern is expected to persist through Friday night.  According to the National Weather Service, the Eastern Kenai peninsula could get another 3-6 inches of rain through Friday afternoon.  Freezing levels will also increase to 4000-6000 feet elevation. 

Today looks like the warmest yet.  Rain will continue, transitioning to snow around 2400 feet.  Wind at the ridge tops - Southeast 28-40 mph. 

The first sign of a break from this pattern is on Saturday, with a chance of partly sunny skies.

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

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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
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