The winds from last weeks storm did a great job of building windslabs in the higher elevations of the advisory area. These slabs have been found on east, north and west facing aspects as well as slopes below rocky or steep headwalls. These slabs are slowly stabilizing, but it could still be possible to trigger one in steep terrain.
Some of these windslabs formed on the crusts that developed during our last high pressure. Look for clues like cracking and collapsing as well as other obvious signs of windslab like a textured or scalloped snow surface or pillows and drifts as you are moving through the mountains today. Additional snowfall on Friday evening also did a great job camouflaging some of these obvious clues so pay attention to the way the snow feels as you travel today. If you encounter a hollow, punchy, or drummy feeling snow surface you are on windslab. Snowmobiles may have more of an affect on these slabs than skiers. Wind slabs often let you get well out on to them before they fail, leaving you in the middle of the slab when it is triggered.
With temperatures climbing back into the mid 40's over the next few days and mostly sunny skies, we can expect a rise in loose/wet, roller ball and point release avalanche activity on steeper aspects affected by the sun and rising temperatures. The likelihood of loose wet slides continues to increase today with the higher than normal temps, and the danger of wet avalanche activity will continue to rise through the day Friday.
In addition large cornices have developed on many northerly aspects this winter and have already begun to fail, so keep your eyes open for what is above you. As the temps climb, more of these big cornices are going to fail. When the temperature climbs, you will need to find cooler slopes or call it a day.
Ladies, Don't forget about our Diva Avalanche Class this weekend at Tamarack Resort. Show up early for yoga and coffee or come just for the class. Stay late for Happy Hour at Seven Devils Pub! Suggested donation of $10 for the Friends of the Payette Avalanche Center.
For more information or to RSVP email: email@example.com
Based on our stability tests, and lack of recent avalanche activity, we are phasing the deep slab/persistent weak layer problem out of the advisory for now. If (or when) temperatures allow melting water to percolate through the snowpack we could see this particular boogeyman make another visit to the West Central Mountains. Keep this layer in mind if you are skiing or riding on protected northerly slopes with a steep, shallow snowpack because you could still be unlucky enough to find a trigger point for a large and unsurvivable avalanche.
Another warm day is on tap for today, with temps in the high elevations reaching the low 40's. Winds will be out of the west-southwest and top out at 8-10 mph. Tomorrow will be even warmer, with highs in the mid 40's. A low pressure will break up the warm temps and sun just in time for the weekend. Showers will start late Friday night/early Saturday morning with a rain/snow line at 5500 feet and dropping through the day 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.