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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   Wendy Wagner  
Thursday, February 16th 2012
Created: Feb 16th 6:57 am
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.
 Show the Complete North American Avalanche Danger Scale
Anchorage Snowmobile Club
The Bottom Line
Good morning. This is Wendy Wagner with the Chugach National Forest Avalanche Information Center on Thursday, February 16th 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 CONSIDERABLE avalanche danger today for wind slab avalanches on all slopes with recent wind deposited snow. These are likely to be dangerous and unmanageable if triggered. High winds with snowfall yesterday, as well as an expected increase in wind later today, will keep human triggered wind slabs likely. The avalanche danger is expected to rise tonight with the approach of anCNFAIC Staff storm.

AVALANCHE DISCUSSION
After the excitement of a mostly clear day on Tuesday to view the avalanche activity after Monday's storm, we are again shrouded in clouds today as to the extent of the natural avalanches produced from yesterday's high winds and 10-20" of new snow. The one exception was a bit of blue sky that poked through in the Summit Lake area where a few recent natural wind slab avalanches were seen.

Primary concern:
Wind slab avalanches that formed yesterday, as well as fresh slabs forming today, will be the primary concern. All slopes that show signs of wind loading (rounded, smooth, rippled and pillow looking surfaces) are very suspect to slide. These slabs are stiff in many areas which can lure a person onto them and release above you. Steering clear of all wind loaded slopes above 35degrees today will be prudent.

Secondary concerns:
Soft slab avalanches and sluffs within the storm snow from both Monday and Wednesday will still be possible as the new snow is currently adjusting to continual loading. These will be found in areas where the snow has been minimally wind affected, most likely below treeline on the steeper rollovers.

Low elevation concerns:
For those traveling in the lower elevations (for example, Placer Valley), there have been a few disconcerting avalanches seen that are suspect to have released on buried surface hoar. Keeping a keen eye out for recent avalanches and avoiding travel under steep slopes on valley bottoms is advised as this kind of avalanche can break above you.

A reminder, Alaska DOT crews have been working non-stop removing the copious snow at Turnagain Pass and parking lots may still be in the process of being cleared. Remember to give the snow removal crews time, and space, to get these lots cleared.

MOUNTAIN WEATHER
Yesterday, just one more storm rolled through our neighborhood since the warmer/wet and windy pattern moved in on February 1st (check out the weather chart for the first half of February). In fact, it marked roughly the 7th system in the past 15 days, with anCNFAIC Staff on tap tonight - and yet anCNFAIC Staff this weekend. Easterly winds that have been raking the region, did so yet again yesterday with averages between 45 and 60mph and gusts over 90mph. The snow/rain line began at sea level and moved up to around 200' by the evening.
Estimated storm totals for yesterday-
Turnagain Pass: 14-20" snow (1" water equivalent)
Girdwood Valley: 10-12" (.8" water equivalent)
Summit Lake: 2-4" (.2" water equivalent)

A brief break between storms last night will continue through mid-day with cloudy skies, intermittent snow showers (adding 2-4") and east ridgetop winds ~20-30mph. Late this afternoon, the next system's front moves in. Expect the east ridgetop winds to ramp up to around 50-60 mph and snowfall to increase, adding around 6-12" tonight. Temperatures that dropped overnight to around 30F at sea level and 20F at 4000' should increase to the mid 30's and mid 20's respectively today. The rain/snow line with this system looks to be right around sea level.

CNFAIC Weather Page and the NWS forecast

Kevin will issue the next advisory Friday 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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