THIS AVALANCHE ADVISORY EXPIRED ON January 21, 2018 @ 6:41 am
Avalanche Advisory published on January 20, 2018 @ 6:41 am
Issued by George Halcom - Payette Avalanche Center
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The avalanche hazard is Moderate above 6000 feet today.  Up to 18 inches of light new snow has potential to sluff. The combination of gusty winds from multiple points on the compass and over a foot of new snow have created new wind slabs on exposed terrain.  Below 6,000 feet the avalanche hazard is LOW.

How to read the advisory


  • Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
Avalanche Problem 1: Loose Dry
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Yesterday we observed about 18 inches of new snow that had a tenancy to want sluff, or to run with you on steep slopes. Many steep slopes have already slufffed naturally. Use caution, and good sluff management while riding or skiing in exposed terrain where you may get knocked off course, and into the many obstacles that have yet to be buried like rocks and trees. 

Avalanche Problem 2: Wind Slab
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This great storm that started on Thursday brought with it gusty winds that started from the Southeast and wrapped around the compass to the West during the day.  Wind speeds at Granite Mt were recorded near 30 mph.  The combination of a significant snowfall and wind will have created wind slabs on exposed upper elevation terrain.  These slabs are  going to likely be just below the ridgelines, but may form well down into the midslope....Pay attention to changes in the texture or look of the snow pack in areas that saw the direct effects of the winds and expect newly formed wind slabs on a variety of slopes today.   Cracking, or sudden changes in how deep you are traveling in the snow pack are indicators of wind slabs.   

We observed natural wind slab avalanches on E,NE slopes yesterday in the Grassy twins and Hazard Lakes area, and also got a report in the Titus lot from a local sledder of a natural wind slab that had pulled out during the storm about 18 inches deep. Time will likely heal the wind slab problem, but stay alert in wind loaded terrain.

recent observations

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Yesterdays storm laid down around 18 inches of snow that is resting on a thin crust that formed from the warmup. The upper 9 inches of new snow right now is very light density, the kind that snow lovers smile about, while checking for sluffs. Our test results on the crust were moderate in compression, but lacked energy to propigate. The rest of the snowpack seemed damp still, but on the path of freezing.

We observed natural wind slab avalanches on E,NE slopes yesterday in the Grassy twins and Hazard Lakes area, and also got a report in the Titus lot from a local sledder of a natural wind slab that had pulled out during the storm about 18 inches deep. Time will likely heal the wind slab problem, but stay alert in wind loaded terrain.

 

Disclaimer

This avalanche advisory is provided through a partnership between the Payette National Forest and the Payette Avalanche Center. This advisory covers the West Central Mountains between Hard Butte on the north and Council Mountain on the south. This advisory applies only to backcountry areas outside established ski area boundaries. This advisory describes general avalanche conditions and local variations always occur. This advisory expires at midnight on the posted day unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.