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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   Kevin Wright  
Saturday, January 15th 2011
Created: Jan 15th 6:53 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 backcountry travelers this is Kevin Wright with the Chugach National Forest Avalanche Information Center on Saturday, January 15th 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).

ANNOUNCEMENT
Were starting an incentive program to encourage everyone to submit snow and avalanche observations. Each quality observation will earn you one chance to win a monthly prize. At the end of this season all the submissions will go into a drawing for an avalanche beacon. Thanks for all the great work, and keep sending in those observations!

BOTTOM LINE
The avalanche hazard rating is MODERATE today. Human triggered avalanches are possible. If you know where to find avalanches I think you could make them happen. Overall confidence to make correct assessments is low due to poor snow structure.

AVALANCHE DISCUSSION
The overall hazard rating is going to stay at Moderate today. The concern is that human triggered avalanches are still possible if you hit the shallow zones where you can affect the weak layers with body weight. The last storm ended more than a week ago and the likelihood of triggering avalanches continues to decline as time goes on. The structure of our December snowpack still gives us concern however and keeps our confidence of correct assessment low.

We may be entering a period of little reactivity, but with a textbook unstable layering structure. Over the last week the tracks we have seen have been relatively conservative and in alignment with what weve been recommending. The most recent reported avalanche was a skier triggered on Sunday 1-9 (see photo gallery). Just because we havent received CNFAIC Staff reports of newer avalanches doesnt mean that you wont find them. As people start to push out onto steeper terrain this weekend they might find the instabilities again. Current conditions make decision making difficult. A rule of avalanche science is to never trust surface hoar, or facets. We have lots of both all over the place. My honest advice is to travel with caution, dont hang it out too far, and try to enjoy the backcountry with a healthy dose of good common sense.

The safest areas to travel this weekend are lower angle slopes. If you find yourself on steeper 35-40 degree terrain I would try to stay in deeply loaded areas where you are less likely to affect the weak layers. This is difficult to assess because the depth of the new snow is so variable due to wind loading during the last storm. Every exposed rock has a shallow zone around it and is a potential trigger point.

Think about your slope angles today. This extreme example was on Seattle ridge shortly after the storm ended. The crown broke high on the convex roll up to a slope angle of 19 degrees in this spot.

484-DSC_7798.jpg


Weve investigated a number of different avalanches since the last storm, and the common thread is that they fail on multiple different weak layers. Buried surface hoar seems to be initiating the larger avalanches, then they step down to deeper layers around the Thanksgiving rain crust.

Encyclopedia of avalanche terms.

WEATHER ROUNDUP
Partly cloudy skies are expected today. Temperatures have dropped since yesterday, negative temps can be found at the valley floors and at ridge tops. The last new snow was 10 days ago. Wind has been light to moderate through the week with gusts occasionally into the 40s. Lots of people have been reporting wind affected snow and scoured areas. Weather is forecasted to remain the same for the next several days. Light to moderate wind and mostly clear skies until Wednesday.

Lisa will issue the next advisory tomorrow morning at 7am. If you get out in the backcountry give us a call at 754-2369 or send us your observations using the button at the top of this page. Thanks and have a great day.

The NWS weather forecast for:
WESTERN PRINCE WILLIAM SOUND-
INCLUDING...WHITTIER...SEWARD...GIRDWOOD...MOOSE PASS
500 AM AKST SAT JAN 15 2011

...STRONG WIND EARLY THIS EVENING THROUGH SUNDAY AFTERNOON
NEAR WHITTIER...

.TODAY...PARTLY CLOUDY. HIGHS 10 BELOW TO 5 ABOVE INLAND AND
IN THE TEENS ALONG THE COAST. LIGHT WINDS INLAND. NEAR SEWARD
AND WHITTIER...NORTH AND WEST WIND INCREASING TO 15 TO 30 MPH.
GUSTS TO 40 MPH NEAR WHITTIER IN THE AFTERNOON.
.TONIGHT AND SUNDAY...CLEAR. LOWS ZERO TO 15 BELOW INLAND AND
5 TO 10 ABOVE ALONG THE COAST. HIGHS 10 BELOW TO 5 ABOVE INLAND
AND IN THE TEENS ALONG THE COAST. NEAR WHITTIER...WEST WIND
20 TO 30 MPH WITH GUSTS TO 50 MPH. NEAR SEWARD...NORTH WIND
15 TO 30 MPH. ELSEWHERE...LIGHT WINDS.
.SUNDAY NIGHT...CLEAR. LOWS 5 BELOW TO 20 BELOW INLAND AND
SINGLE DIGITS ALONG THE COAST. NEAR SEWARD AND WHITTIER...
NORTH AND WEST WIND 15 TO 30 MPH. ELSEWHERE...LIGHT WINDS.
.MARTIN LUTHER KING JR DAY...MOSTLY SUNNY. HIGHS 10 BELOW
TO 5 ABOVE INLAND AND 15 TO 20 ALONG THE COAST. VARIABLE
WIND TO 10 MPH EXCEPT NORTH WIND 10 TO 20 MPH NEAR SEWARD.
.MONDAY NIGHT...PARTLY CLOUDY. LOWS 10 BELOW TO 5 ABOVE.
.TUESDAY...PARTLY CLOUDY. HIGHS ZERO TO 10 ABOVE.
.TUESDAY NIGHT...PARTLY CLOUDY. LOWS ZERO TO 10 ABOVE.
.WEDNESDAY...MOSTLY CLOUDY WITH A CHANCE OF SNOW SHOWERS.
HIGHS 5 TO 15 ABOVE.
.WEDNESDAY NIGHT AND THURSDAY...MOSTLY CLOUDY WITH A CHANCE
OF SNOW. LOWS 5 TO 15 ABOVE. HIGHS IN THE TEENS.
.THURSDAY NIGHT AND FRIDAY...MOSTLY CLOUDY WITH A CHANCE
OF SNOW. LOWS IN THE TEENS. HIGHS 15 TO 25.


TEMPERATURE / PRECIPITATION

SEWARD 14 7 14 / 0 0 0
GIRDWOOD 4 -6 2 / 0 0 0



WEATHER STATION SUMMARY for Turnagain Pass:
-3800 Sunburst Wx Station-
Currently 2 degrees. Light wind with a recent gust to 28 from the ENE.
-2600 Seattle Ridge Wx Station-
Current temperature 2. Wind in the teens from the SE.
-1800 Center Ridge Wx Station-
Temperature 3 degrees. No new snow in the past week.




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

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
© 2017 Chugach National Forest Avalanche Information Center. All rights reserved.
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