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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   Wendy Wagner  
Monday, February 13th 2012
Created: Feb 13th 7:00 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
Good morning. This is Wendy Wagner with the Chugach National Forest Avalanche Information Center on Monday, February 13th 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
A HIGH avalanche danger has been issued for the Eastern Turnagain Arm area. Heavy snowfall and high winds are currently loading slopes, natural avalanches are likely and human triggered avalanches are very likely. Today the message in simple: Avoid all avalanche terrain, including any location near and under avalanche prone slopes. If you are uncertain as to exactly where these areas are then backcountry travel is not recommended.

AVALANCHE DISCUSSION
Yesterday, the only avalanche activity we heard of, or saw, were a few point release moist snow avalanches. These were caused by the quick shot of sun heating up the new snow that fell Saturday. A couple of these ran 100-200 in steep gully features. Most folks were taking things quite conservative (including myself) with the close calls from Saturday.

Heavy snowfall and high winds = HIGH avalanche danger - once again. A natural avalanche cycle has likely begun and should continue through the day. Snow is falling at all elevations and on a variety of surfaces from slick crusts below treeline, to wind slab above treeline, and soft snow in between. The slick surfaces will encourage slides to move fast and run far but, the intense wind with the new snow will increase the hazard regardless of these surfaces.

Storm snow instabilities such as wind slab and soft slab avalanches as well as sluffs will be the game today. Temperatures look to be cool enough to limit widespread wet activity, but we are hovering right at that line and wet avalanches are possible at the lower elevations.

Note:
This is the 15th day since the temperatures turned warm and we lost those savored cold blower powder conditions. The Turnagain SNOTEL site has seen 8.5 of water since the warm up and you can roughly double that for the mid to upper elevations thats around 16, or more, of water weight in two weeks. This is a lot of load to add to the pack and the potential exists for avalanches to break into the older snow. There is uncertainty with this potential however, the cold dry snow from January, though long buried in many areas, still exists and is thought to have been the culprit in the Summit Lake 2/11 avalanche. Additionally, there are many interfaces within the last two weeks of storm layers and some of these have shown stubborn failures, but failures nonetheless and good to keep in mind with continual loading.

For those interested, more details have been added to the events of the full burial at Petes North on Saturday (2/11) HERE.

MOUNTAIN WEATHER
Yesterday's lull in stormy weather brought some patches of blue and welcome sunshine to Turnagain Pass while intermittent rain and snow showers were more prevalent near Gridwood. Winds were occasionally gusty but died down in most locations with averages near 20mph and gusts in the upper 30's. Temperatures remained mild, mid 30s near sea level and the low 20's on the ridgetops.

Today, we have yet anCNFAIC Staff storm that has nosed in overnight, though this one is slightly cooler, bringing snow to all elevations. Snowfall began in the late evening and around 12" has accumulated at Turnagain Pass with anCNFAIC Staff 8-12" expected to fall through the day. A bit more is likely in the Girdwood Vally with only 2-6" inches in the Summit region. Easterly winds have pick up significantly overnight and are currently averaging 60mph with gusts around 80mph. Ridgetop temperatures should hover near 20F and at sea level 33-35F. Wind from the east is forecast to remain strong, sustained around 50mph with gusts near 75mph.

This system should move out tonight and bring a lull in the weather for Tuesday.

CNFAIC Weather Page and the NWS forecast

Graham will issue the next advisory tomorrow 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: Mar 28, 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: OpenPlacer remains open but SKOOKUM DRAINAGE will close to motorized use on April 1st.
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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