The winds have howled during the last storm that caused widespread natural avalanches yesterday, So be on the look out for wind slabs in likely and unlikely places (below cliffs, cross-loaded slopes). These new wind slabs are going to be reactive on all leeward (downwind) aspects over 30 degrees that have obvious signs of wind loading (smooth rounded pillow like snow surface) and could range from 6 inches to 3 feet in depth. The tricky part about our current conditions, is that due to the high winds yesterday, these wind slabs could be located mid-slope on steep open faces. This will allow you to get half way down a slope before getting into trouble.
We have buried one of the nastiest layers known to snow. Surface hoar that formed during our last extended cool, dry weather is now buried 33CM/ 1 foot down, and is showing potential for propigation. Natural avalanches went yesterday on many wind loaded Northern and Eastern slopes...This problem layer has the potential to linger for a while in our snowpack, and is a very common factor in avalanche fatalaties...take the time to dig, and evaluate every slope above 30 degrees, and stay far fromthebottom,or run-outof steep slopes!
This foot of new, dry, cold snow has the potential to run with you, or sluff. Pay attention to your sluff it can knock you off your feet, and put you into places you would rather not be.
It is game on for avalanche conditions in the backcountry! Slopes over 30 degrees warrent respect and patience. With 12 inches of new snow and the perfect making of an avalanche (surface hoar/facets with a new slab on top) these are prime condintions to get into trouble if you do not carefully evaluate the snowpack and make conservative decisions. Keep to low angle slopes in sheltered terrain today and enjoy the cold low angle powder.
Yesterday we toured a large chunk of the advisory area, and we were not suprised to find fresh evidence of natural avalanches on mainly Northern aspects that went on a layer of buried surface hoar (33CM Down) that formed during our cool dry spell. The winds overloaded this layer, and it is still buried, waiting for a trigger in many other places. More snow will ramp up the danger on this persistant weak layer. We had simiar reports from Tamarack, but also on South aspects there.
Expect the Wset winds to calm down today, and a high temperature near 27 in the upper elevations, and just a bit warmer in McCall...our next round of snow should start on Saturday.
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.