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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   John Fitzgerald  
Monday, March 16th 2015
Created: Mar 16th 6:54 am
4 High Alpine / Above 2,500' Travel Advice: Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
3 Considerable Treeline / 1,000'-2,500' Travel Advice: Dangerous avalanche conditions. Careful snowpack evaluation, cautious routefinding and conservative decision-making essential.
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
Special Announcement

An avalanche accident involving a snowmachiner occurred over the weekend near Denali National Park.  Our thoughts are with the patient for a full recovery.  More details can be found HERE.


The Bottom Line

The avalanche danger will climb to HIGH in the Alpine and CONSIDERABLE at Treeline by the end of the day.  Slabs up to 18” thick will be very sensitive to human triggers and could release naturally.  

Dangerous conditions exist and require advanced travel and snowpack assessment skills.  Avalanches have the potential to run through multiple elevation bands.  Because of this, awareness of terrain looming overhead will be critical today and is why the danger will be MODERATE below Treeline in big channeled terrain.


Primary Concern

Rapid loading as a result of new snow and wind will create unstable conditions today.  Slabs will vary in size and be thickest, up to 18” on leeward slopes.  With wind speeds over 40 mph expect loading to occur lower down on slopes and in areas that are normally protected from the wind.

The danger will be more in the MODERATE range in general this morning.  That will change quickly as the day progresses.  Becasue of this it will be important to pay attention to rapidly changing conditions and pick your terrain carefully.

Recent avalanches, shooting cracks, and collapsing are key indicators of unstable snow.  These signs should dictate where you travel today.  In other words, avoid avalanche terrain if and when you begin noticing these signs.

Travel in the Alpine elevations is not recommended for the latter part of the day.


Mountain Weather

Low pressure currently centered over the Alaska Peninsula has brought precip, wind and warmer temps to the area.  Temperatures over the last 24 hours have seen a dramatic rise with ridgetops moving from 0 to 20 deg F.  Winds have picked up in a similar dramatic fashion, with ridegtops reporting speeds in the 35-40mph range this morning.  Storm totals so far are in the 5”/.4” (snow/H20) range.

Today expect snow to be heavy at times with up to 10”/.9” (snow/H20) of additional accumulation by the evening.  Winds will be strong out of the East at 30-40mph.  Temperatures will be in the low 30s F at 1,000’.  Rain/snow line will hover between 500-1,000’.

Precipitation will taper off late this evening.  Cloudy and showery conditions will continue through Tuesday with another round of significant precipitation on Wednesday.

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

  Temp Avg (F) Snow (in) Water (in) Snow Depth (in)
Center Ridge (1880') 21 5 .3 47
Summit Lake (1400') 22 1 .1 9
Alyeska Mid (1700') 21 6 .4 31

 

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

  Temp Avg (F) Wind Dir Wind Avg (mph) Wind Gust (mph)
Sunburst (3812') 12 ENE 26 76
Seattle Ridge(2400') 15 na 24 48

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 15, 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: Open
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
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