This morning the avalanche danger is LOW but will rise to MODERATE. Sunshine and warming will contribute to wet avalanches and weakening cornices. Lingering wind slab instabilities exist at upper elevation. Evaluate wind loaded terrain, avoid cornices and stay off sunny slopes once they soften. Safer riding conditions and better snow quality exist on shady aspects at low and mid elevations.
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Above 6500 ft.
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5000-6500 ft.
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3500-5000 ft.
Yesterday's warming and sunshine initiated a small loose wet avalanche cycle on sunny aspects. Today, slightly warmer temperatures and less cloud cover could produce additional loose wet slides particularly at upper elevations that remained relatively cool. Cold overnight temperatures have formed a crust on aspects warmed yesterday. After this crust breaks down natural and human triggered slides will be possible. If you find yourself breaking through the crust and sinking into the moist incohesive snow below it is time to move to a different aspect. Rollerballs and pinwheels are a good indicator that the surface snow is warming. Avoid traveling in or above terrain traps and long-running gullies while the surface snow is moist.
On Thursday/Friday, snow and moderate southwest winds formed slabs up to 2-3' thick on leeward aspects at upper elevations. Yesterday's warm weather helped these slabs to strengthen. However, it has only been 36 hours since the recent storm ended and lingering wind slab instabilities may exist. Avoid lens-shaped pillows below ridgelines and on steep convex or cross-loaded terrain. Cracking in the snow is a sign of instability with shooting cracks an obvious red flag! Evaluate all wind loaded terrain before committing to a slope.
Due to their immense size cornices gradually weaken during multi-day warming events. Therefore, expect cornices to be less stable than yesterday. Cornices can fail without warning and resulting debris may trigger a deeper slab avalanche on the slopes below. These features extend much further beyond solid ground than expected. Avoid traveling on or below cornices during this weakening phase.
Yesterday's sunshine and warm temperatures initiated a natural wet loose avalanche cycle on sunny aspects. Resulting slides were relatively small and mostly D1 (observation 1, observation 2). Partly cloudy skies prevented this cycle from reaching its full potential. Today we are expecting fewer clouds and warmer temperatures which may lead to slides on slopes that were not affected yesterday. This morning we can expect to find a surface crust on aspects warmed yesterday. This crust will allow the surface to remain stronger for a longer period than yesterday. However, once the crust breaks down avalanche conditions deteriorate rapidly.
Cornices around the area are HUGE!. The likelihood of a cornice failure will increase over the next few days with continued warming. Continue to give cornices a wide berth; they have grown to dangerously large sizes this season and can also act as triggers for larger avalanches (photo).
Don't miss out on our final two avalanche education lectures this season at Penco Power Products in Kalispell and Whistling Andy Distillery in Bigfork. Thanks to all who participated in our avalanche education program this season and we're already planning next years line-up!
High pressure continues to build with slightly warmer skies and less cloud cover than yesterday. the trend continues through tomorrow and possibly Tuesday. Unsettled weather moves into our area Wednesday.
| Sunday | Sunday Night | Monday | |
|---|---|---|---|
| Cloud Cover: | Mostly sunny | Clear and cool | Continued sunny |
| Temperatures: | 35 to 40 deg. F. | 15 to 20 deg. F. | 37 to 42 deg. F. |
| Wind Direction: | SW | S | SW |
| Wind Speed: | 1to 11mph | 1 to 11 mph | 0 to 5 mph |
| Snowfall: | 0 in. | 0 in. | 0 in. |
| Snow Line: |
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.
