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This is Janet Kellam of the Sawtooth National Forest Avalanche Center with your Backcountry Avalanche Advisory and Weather Forecast for Tuesday, February 9, 2010 at 7:30 am.
The Wattis Dumke Foundation & the Friends of the Sawtooth Avalanche Center bring you this advisory.
Bottom Line by Region:
 North Wood River Valley
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The avalanche danger is estimated to be MODERATE. Potentially dangerous avalanche conditions remain on some slopes, particularly mid to upper elevation cooler aspects such as those facing east through north through west.
Weak faceted snow buried 2-3 feet deep is still capable of producing a large, catastrophic avalanche. Slopes where you could trigger an avalanche are becoming more isolated, but the snowpack remains unpredictable and it’s very difficult to evaluate which slopes are safe and which are not. A conservative approach to steeper terrain remains the best tactic. Use extra caution on slopes steeper than 35 degrees with shallow, rocky areas or steep rollovers.
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 South & Central Wood River Valley
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The avalanche danger is estimated to be MODERATE. Potentially dangerous avalanche conditions remain on some slopes, particularly mid to upper elevation cooler aspects such as those facing east through north through west.
Weak faceted snow buried 1-2 feet deep is still capable of producing an avalanche, but the likelihood of triggering is decreasing with time and dangerous slopes are becoming more isolated. The unusually weak structure of the snowpack in this region warrants a conservative approach on any slope steeper than 35 degrees.
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Salmon Headwaters & Sawtooth Mountains
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The avalanche danger is estimated to be MODERATE. Potentially dangerous avalanche conditions remain on some slopes, particularly mid to upper elevation cooler aspects. The greatest concern is the southern end of this region closer to Galena Summit, where weak faceted snow buried 2-3 feet deep is still capable of producing a large, catastrophic avalanche. In the northern end of the Sawtooths the snowpack is showing improved stability, but the facets buried 3-4 feet deep remain a concern and steep slopes should be evaluated carefully.
Slopes where you could trigger an avalanche are becoming more isolated, but the snowpack remains unpredictable and it’s very difficult to evaluate which slopes are safe and which are not. A conservative approach to steeper terrain remains the best tactic, and use extra caution on slopes steeper than 35 degrees with shallow, rocky areas or steep rollovers.
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Soldier Mountains
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We provide the Bottom Line for the Soldier Mountains on Friday, Saturday, and Sundays at 7:30am. Please continue to read the full advisory as the information may be applicable to this region.
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Primary Avalanche Concern:
The weak December snow at the base of the snowpack is widespread and remains a concern. We have received very little new snow in over two weeks so the snowpack has adjusted and the avalanche danger has decreased. However, it is still possible to trigger an avalanche due to the very poor foundation beneath our January snow accumulation. Areas where it is more likely to trigger an avalanche will be steeper terrain, rocky sections and sharp rollovers where a slope suddenly becomes much steeper. Shallower snowpack areas present the most risk as the weight of a person is more likely to impact the buried weak layers.
Layers of buried surface hoar have been reported one and two feet deep in a variety of places on cooler aspects. These layers show clean shears but have not been reactive in stability tests. Continue to look for buried surface haor layers and remember slopes where they are found as these layers may become reactive with any additional snow.
The January snow has become a firm, hard slab and is capable of producing a large avalanche. Safe travel practices remain mandatory- one person on a slope at a time, watch each other carefully from safe locations. Communicate well within your group about risk, the choices you make and the possibility of having to perform a rescue. Are you prepared for this?
South of Jackson Hole, the Grays River region has a snowpack similar to our Central and South Wood River Valley. This area received moderate amounts of snowfall last week. Saturday a snowmobiler was killed while traveling on a high elevation steep slope. In addition a very close call occurred in the same region. Keep in mind the avalanche danger will increase in our area when our buried weak layers are subjected to a new load of snow.
It is now possible to venture into more terrain than we have been able to all year. Cautious travel and careful route selection should still be on everyone’s radar screen.
Current Conditions:
Yesterday’s strong sun felt warm, but temperatures remained cool in the shade. Daytime highs were 20-24 degrees between 9,000ft to 10,000ft in elevation, and only 31 degrees on the valley floor. Winds remained light. This morning all elevations show cool temperatures with 0 degrees in Ketchum and 10 degrees at upper elevations.
Varied sun crusts have developed on any sunny aspects, but recrystallized powder and surface hoar provide very good surface conditions on the shaded slopes. The snowpack is mostly supportive at mid to upper elevations, but less supportive and often punchy conditions can still be found below approximately 7,000feet.
Mountain Weather Forecast:
With clear skies early this morning, today looks like another very nice day. Temperatures will start out cool this morning with a slight temperature inversion, but are expected to rise into the low twenties at upper elevations and could reach the mid thirties on the valley floor. Winds should remain light and shift from the southeast to a more westerly direction. Some clouds may move over our region today and tomorrow as southern California gets yet another storm system.
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| Reported Conditions |
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| Temperatures |
| Overnight Low |
10 |
10 |
0 |
| 6am Temperature |
10 |
11 |
0 |
| 24 hr Maximum |
24 |
20 |
31 |
| Winds |
| Current Winds |
6SE |
11 |
- |
| 24 hr Average |
3 |
NA |
- |
| Maximum Gust |
10SW |
NA |
- |
| Snow - Storm Interval # 18 |
| Total Depth |
45" |
53" |
24" |
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Announcements:
Accident reports can now be found on our new accident page:
http://www.sawtoothavalanche.com/accidents.php
The annual Warm Springs Winter Elk Closure is in place - this prohibits all travel on the Warm Springs south facing slopes from Wanderer's Way in Ketchum out to the West Fork.
A fund has been set up to help the Michael family through the Bald Mountain Rescue Fund, a non-profit established to assist ski community individuals and families after serious accidents. All contributions are tax-deductible and go directly to assist the family during this time of great loss. Please send all donations to:
Bald Mountain Rescue Fund/Michael Family
c/o Brian Barsotti
PO Box 370
Ketchum, ID 83340
The Avalanche Rescue Training Park is located in the Festival Meadows, next to Our Lady of the Snows Catholic Church on Sun Valley Road. It is free with easy instructions on the control panel and open all day. All you need is a beacon and probe to practice your skills. Snow shoes or touring skis are recommended to get around over the snow.
The beacon practice area on Baldy is now located near the trees in the center of Christmas Ridge.
To find out where Sun Valley Heli Skiing plans to operate on any given day, call their status line at 622-2999.
Your observations are invaluable! They help us produce more accurate advisories which in turn helps you. If you get into the backcountry, let us know what you see out there - especially if you see or trigger any avalanches. Call (208)622-0099 or fill out the observer form on our website: http://www.sawtoothavalanche.com/submit_observation.php
Check http://www.wrh.noaa.gov/pih/ for the latest weather forecasts.
For Idaho road closures check http://511.idaho.gov
For a recording of this advisory, call the Avalanche Hotline - (208)622-8027.
This information only applies to the backcountry and does not apply to highway programs or operating ski areas. Changing conditions and local variations may occur.
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