US Forest Service ARCHIVED avalanche advisory for the Idaho Panhandle This is archived for reference relating to a fatal incident on Jan 11 General Avalanche Information Kootenai Issued: Thursday, January 11, 2024 - 7:00AM Expires: Friday, January 12, 2024 - 7:00AM Author: Ben Bernall THE BOTTOM LINE Recent snowfall and winds have created slabs of unstable snow at tree line and above. Human triggered avalanches remain likely on terrain steeper than 30 degrees. Terrain below ridgelines facing north and east has been loaded by winds, slabs will be more dangerous and likely to be triggered in those locations. Forecast Discussion There has been a report of an avalanche incident near Stevens Peak today. We are aware of the incident and an investigation will take place as soon as possible. At this time rescue efforts are in progress. On Thursday the "avalanche warning" that was present Tuesday through Wednesday is being discontinued. It is important to know that conditions remain dangerous out there for backcountry riders. Although we do not meet criteria for HIGH avalanche danger, it is strongly advised that you avoid riding in steep terrain today, especially in locations that are loaded in by the recent winds. Thursday we are also predicted to see another decent shot of snow across the area that will bring in a wind shift as the day progresses. Anticipate winds to shift to a more northeasterly pattern as a cold front moves into the area. Winds will be blowing between 20-30 mph at upper elevations by this afternoon creating the potential to create wind loading in locations facing south and west, opposite of our general wind loading patterns. This system is bringing in some very cold temperatures that have been well advertised this past week, so I won't belabor that issue. The next advisory will be posted by 7 a.m. on Friday! Forecast from the Previous Day Backcountry Avalanche Forecast St. Regis & Silver Valley Issued Wednesday, January 10, 2024 - 8:39AM Expires Thursday, January 11, 2024 - 7:00AM Author Mikey Church/Ben Bernall THE BOTTOM LINE The avalanche danger will remain HIGH on Wednesday at upper elevations. Fresh wind slabs have been created on northwest to northeast facing slopes at upper and mid elevations and will be easily triggered today. Lookout for signs of instability such as cracking underfoot. Good skiing and riding can be found in low angle terrain that is sheltered by the trees. Avalanche Danger For January 10 and 11, 2024 Above Treeline (Above 6500') 4 - High Near Treeline (5,500-6500') 3 - Considerable Below Treeline (Below 5,500') 2 - Moderate Avalanche Problems (2) Problem #1: Wind Slab Aspect/Elevation: NW - N - E, Near and Above Treeline (Above 5500') Likelihood: Very Likely Size: Small (D1) to Large (D2) The recent storm delivered a much needed refresh with as much as 20" of light snow, with additional snow continuing to fall throughout the day on Tuesday and Tuesday night. This new snow was accompanied by strong winds, 30mph with gusts near 60mph, consistently blowing from the southwest. With plenty of snow available for transport, reactive wind slabs will form below ridgelines and cross load terrain features like gullies. Stay aware of wind loaded areas and density changes underfoot and seek lower angle skiing and riding if you experience shooting cracks under your skis or snowmobile. Additional snowfall and winds will accompany an approaching cold front on Thursday. This will add to the wind slab issue and create some bitterly cold conditions across the area into the weekend. Problem #2: Persistent Slab Aspect/Elevation: W - N - E, Near and Above Treeline (Above 5500') Likelihood: Possible Size: Small (D1) to Large (D2) A new layer of surface hoar formed on 1/1 and was buried intact by the most recent storm cycle. This buried surface hoar was preserved on less sun affected slopes and can be found intact on north facing aspects. We have also found a weak layer of facets above the December 20th rain crust. Deeper in the snowpack, the late November surface hoar is harder to find and less reactive in isolated areas on north facing slopes, but we are not ruling it out until we see evidence that it is no longer a threat. With the new snow load, these persistent weak layers have the potential to become activated. We should treat them with respect until we find evidence that they are no longer a problem. Forecast Discussion Avy Techs Brian and Izzy toured around Burk Summit yesterday. They found that the new snow, although stable, was light density and vulnerable to changing weather conditions we are seeing. Yesterday's pit tests showed relative stability as new snow has come in "right-side up", but continued loading with additional snow and wind throughout the day will see conditions change and avalanche danger increase. New snow makes for great skiing, but it's an opportunity to take a step back and make good decisions. Be careful and avoid steep areas where the winds have hit hard. Very windy conditions from the Southwest will have the potential for consequential avalanches in the upcoming days. This is our greatest concern and will be found in specific locations, such as below the leeward side of ridges or in cross loaded gullies. Even after winds die down, evidence of intense winds effected the snow is indicated by cracking snow, chalky hollow feeling snow that should be avoided in and around avalanche terrain. Wind slabs can be avoided by sticking to sheltered or wind-scoured areas. At mid to upper elevations, we've got double header Avalanche problems: strong winds out of the Southwest and persistent weak layers. IPAC has issued an avalanche warning as avalanche danger is likely to rise between publication of this forecast and by the time it expires. Sometimes, when it’s blowing snow, the best thing to do is talk about it over a beverage with your backcountry friends and wait till the next chance you can get together for better conditions. Stay safe if you are going out and look for signs of instability! Especially near wind affected areas. Shout out to Essex P. , Sean M., and Ari K. for their Observations throughout the Valley. We appreciate the info.