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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   CNFAIC Staff  
Monday, March 26th 2012
Created: Mar 26th 6:46 am
2 Moderate Alpine / Above 2,500' Travel Advice: Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
2 Moderate Treeline / 1,000'-2,500' Travel Advice: Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
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.
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The Bottom Line
Good morning. This is Chris Engelhardt with the Chugach National Forest Avalanche Information Center on Monday, March 26th 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).

BOTTOM LINE

There is a MODERATE avalanche danger for the core advisory area today. Although the snowpack is starting to settle down, the new wind slabs and deeper pockets of fresh snow from Friday nights storm continue to produce small slab avalanches. These hazards are most likely found on leeward catchment areas above tree line and have been reported on all aspects. The upper snowpack also continues to retain persistent slabs with weak layers such as surface hoar and sun crusts/facet combinations generally found 2-3 below the surface.

AVALANCHE DISCUSSION

The northern end of Turnagain Pass has seen the most avalanche action recently where there has been numerous reports of shallow, reactive slab avalanches over the course of the weekend. Along with Wendys observation from Saturday there were additional public observations on Sunday of 6-12 wind slabs sliding on Southwest aspects in Junior Bowl on Seattle Ridge. Most of these pockets have remained isolated to 50-100 wide and are generally running 6-800 vertical if initiated on steeper slopes. Wet loose point releases continue to trickle down southerly slopes in the later afternoon. We have yet to see major wet slab slides on south aspects, but if we continue to get warming temperatures and bright afternoon sun, these will become a much greater concern.

Concern #1 - Wind Slab and Soft Slab

Continue to be on the lookout for fat looking or obviously wind loaded pockets up high. Over the weekend I have found these slabs to extend 20-30 feet downslope just off ridgelines and they definitely feel and sound drummy and hollow. Pay particular attention to cross-loaded areas, where there is a rib, or ridgeline running generally parallel with the main fall line of the slope. These areas in particular seem to be some of the best habitat for tender, lurking, reactive slabs.

Concern #2 Persistant Slab

Dont forget that we still have two weaknesses deeper in the snowpack in the form of buried surface hoar and sun crust/facet combinations. We are still finding clean shears at the sun crust around 2-3 down on south aspects, but these are increasingly harder to make fail. Besides, the skiing and snow machining on sunny aspects is trending towards bad at this point. The buried surface hoar continues to be the little gremlin out there, found in variety of nooks and crannies. Make a mental note of its continued presence, and dig for it 1-2 below the surface on the cooler shadier aspects. Areas most likely to find this problem are northerly aspects around Girdwood, Placer Valley, 20-mile, and Johnson Pass.

Concern #3- Wet Sluffing

If things heat up, continue to avoid travel on, or beneath sunny aspects. This is especially crucial in the later afternoon. 2-3pm seems to be the magic hour for the south aspects to really start cooking right now.

MOUNTAIN WEATHER

It was glorious on Sunday and one of the best days of spring 2012 yet. Bluebird sunshine was found all day over the core forecast area. Winds remained very calm yesterday and by 3-4pm temperatures peaked to nearly 30F on Seattle ridge and around 20F on Sunburst. Winds continued to remain calm overnight picking up to around 10mph from the East early this morning. Temps stayed in the 15-19F range for 2-3000 ft elevations on Sunday night. Temperatures are forecast to be WARM today, mid 30s around 1000ft and its anticipated to be partly cloudy to sunny skies with a 30% chance of precipitation. Winds are slated to pick up from the Southeast into the mid 20mph range for ridge tops today.


CNFAIC Weather Page and the NWS forecast

Graham will issue the next advisory Tuesday 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.

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 16, 2017 )

AREA STATUS WEATHER AND RIDING CONDITIONS
Glacier District
Johnson Pass: Closed
Placer River: Closed
Skookum Drainage: Closed
Turnagain Pass: ClosedThanks all for a safe and fun season on the Chugach NF! Stay tuned for the 2017/18 season. #playsafe #snowtosealevel
Twentymile: Closed
Seward District
Carter Lake: Closed
Lost Lake Trail: Closed
Primrose Trail: Closed
Resurrection Pass Trail: ClosedResurrection Pass trail will be 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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