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Turnagain Area Avalanche Advisory
Thursday, January 14th 2010 7:03 am by CNFAIC Staff
ARCHIVED ADVISORY - All advisories expire after 24 hours from the posting date/time.
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BROUGHT TO YOU BY
The Bottom Line
Good morning backcountry travelers this is Matt Murphy with the Chugach National Forest Avalanche Information Center on Thursday January 14th at 7 am. 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).


WEATHER ROUNDUP
Hindcast (Last 24 hours)

3800 -Sunburst Wx Station-
Temperatures have stayed steady between 23-24 degrees F with light average winds between 2-10 mph out of the E with a moderate max gust of 17 mph
Current temp is 23

2400-Seattle Ridge Wx Station-
Winds have been light averaging 7-16 mph out of the ESE with a moderate max gust of 22mph

1800-Center Ridge Wx Station-
Not working this morning

Nowcast

Most weather stations are down this morning so we have limited real time data. Current temp in Girdwood this morning is 27 and its 23 at 3800 in Turnagain Pass. Winds are currently light at all ridgetop wx stations this morning. The Middleton radar shows steady moderate precip moving N over the middle of PWS, and the Kenai radar shows light precip building to moderate precip moving N directly toward Anchorage.

Forecast

WESTERN PRINCE WILLIAM SOUND-
INCLUDING...WHITTIER...SEWARD...GIRDWOOD...MOOSE PASS
500 AM AKST THU JAN 14 2010
.TODAY...RAIN AND SNOW. SNOW ACCUMULATION 1 TO 3 INCHES. HIGHS IN THE
MID 20S TO MID 30S. LIGHT WINDS.
.TONIGHT...CLOUDY WITH A CHANCE OF SNOW. LOWS IN THE MID TEENS TO
MID 20S...COLDEST INLAND. LIGHT WINDS.
.FRIDAY...SNOW LIKELY. SNOW ACCUMULATION UP TO 2 INCHES. HIGHS IN
THE MID 20S TO LOWER 30S. VARIABLE WIND 10 MPH.
.FRIDAY NIGHT...SNOW. LOWS IN THE LOWER 20S TO LOWER 30S. EAST WIND
10 TO 20 MPH.

Temperature / Precipitation

SEWARD 39 34 40 / 80 60 80
GIRDWOOD 39 22 35 / 60 40 40


Short Term Weather Model Forecasts (NAM, WRF, GFS) for the Kenai Mountains near Turnagain Pass
Sea-level: GFS shows 0.25 inches of water forecasted today
3000: temps forecasted between 23 and 32 degrees F with winds 5 mph
6000: temps forecasted between 14 and 23 degrees F with winds 5-10 mph

AVALANCHE DISCUSSION
Todays weather probably will not contribute to the avalanche danger today at Turnagain Pass. There is some new precip forecasted, but not very much. Plus the winds have been light and the NWS calling for continued light winds today. Todays weather forecast does not look like it will pack too big of a punch.

The main avalanche concern today and for the near future is and will be that slippery rain crust that has been observed as high as 3000 on both sides of the highway at Turnagain Pass. If there was 3 feet of new snow today, then avalanche conditions would be deadly. However, the biggest snow depth measurement has been 10.5 inches of new light density snow at the Eddies parking lot in the past 48 hours. There is probably anCNFAIC Staff inch or two since last night. As far as avalanches, there is not quite enough snow on top of that slippery bed surface to create large avalanches yet, but, small avalanches and sluffs are very easy to trigger on any steep slope at all elevations; so, use elevated caution if you find one of those deeper stiffer pockets of snow especially near ridgelines or highmarking on a steep rollover on Sunnyside.

The new snow has been sneaking up on us because it has been coming in slow and steady, which is OK for today. The weather forecast continues to call for more snow over the next couple days with a bigger storm coming in from the Aleutians. Lets be smart about the rain crust if new snow keeps accumulating over the next couple days. That slippery rain crust is by far the most dangerous weak layer we have seen in our snowpack all season. It will most likely become a serious problem after it gets more snow on top of it.

Todays avalanche danger will remain at LOW with pockets of MODERATE due to small wind slabs near ridgetops, and easily triggered small slabs on steep rollovers at all elevations.

LOW is defined as: Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features. Natural and human triggered avalanches unlikely (except glide cracks are possible). Small avalanches in isolated areas of extreme terrain.

Pockets of MODERATE is defined as heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern. Natural avalanches unlikely, human-triggered avalanches possible. Small avalanches in specific areas; or large avalanches in isolated areas.

A wild card right now are the glide cracks. One of these crevasse like features avalanche on Jan 4th for no obvious or apparent reason (see photo gallery). Nostradamus couldnt have predicted that one; so, it adds to the theory that glide cracks are like cornices in that they are very difficult to predict. Sometimes they avalanche when its cold, sometimes when its warm, sometimes when it rains, sometimes when it snows, sometimes for whatever reason possible. I dont mean to turf this avalanche problem into the unknown, but the avalanche community really does not have a good handle on what causes glide cracks to fail. We have not seen or had any reports of any more glide crack failures in the past week, but it would still be wise to avoid traveling on, near, or underneath the path of any glide cracks.

Always remember that safe backcountry travel requires training and experience. You control your own risk by choosing where, when, and how you travel.

Thanks for checking todays avalanche advisory. The next one will be posted tomorrow Friday January 15th.

 Show the Complete North American Avalanche Danger Scale
1 Low Alpine / Above 2,500' Travel Advice: Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
1 Low Treeline / 1,000'-2,500' Travel Advice: Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
1 Low Below Treeline / Below 1,000' Travel Advice: Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

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 16, 2019 )

AREA STATUS WEATHER AND RIDING CONDITIONS
Glacier District
Johnson Pass: Open
Placer River: OpenVery wet. Travel not recommended until a re-freeze.
Skookum Drainage: OpenNote: The Skookum drainage closes to snowmachines on April 1 annually as per the Chugach NF Forest Plan.
Turnagain Pass: Open
Twentymile: OpenVery wet. Travel not recommended until a re-freeze.
Seward District
Carter Lake: Open
Lost Lake Trail: OpenPlease stay on trail to avoid resource damage through forested areas.
Primrose Trail: OpenPlease stay on trail to avoid resource damage through forested areas.
Resurrection Pass Trail: ClosedClosed for the 2018/19 season. Next season will be open to motorized use.
Snug Harbor: Open
South Fork Snow River Corridor: Open
Summit Lake: Open

Subscribe to the Turnagain Area Avalanche Advisory:

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
© 2019 Chugach National Forest Avalanche Information Center. All rights reserved.
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