Bulletin d’avalanche

2-4" of recent snowfall will not significantly change the avalanche danger today. Very small, dry loose avalanches (sluff) may run on slopes greater than 35 degrees, above 7000'. Cooling temperatures have helped reduce the likelihood of wet loose avalanches above 7000'. Wet, mushy snow may still be found below 7000', beneath surface crusts.

Our winter storm did not really manifest as we hoped. 1-3" of snow fell over the past 24 hours. Another 1-3" could fall over the higher terrain by this evening. With this small amount of new snow, travel conditions may be more dangerous than the avalanche potential. Two nights below freezing has helped to cap our saturated snowpack with stout, melt-freeze crusts at the surface. Small, dry loose avalanches (sluff) could be possible on these surface crusts above 7000', in terrain steeper than 35 degrees. Pay attention to how the new snow has bonded to recently formed crusts. Below 7000', the surface crust may be a little lighter and not as solid. If you find yourself punching through the crust into wet, mushy snow, be heads up for hazardous travel and wet loose snow moving on steep terrain features at lower elevations. Lower elevation creeks and streams are opening up and may pose some challenges to travel.

Spring has been in full swing this past week. Last weekend, there was still cold, soft snow after a series of small storms. Sunday began the trend of a significant warming event that brought temperatures 10-20 degrees above normal. Monday, cornice failures were triggering soft slab avalanches on north-facing terrain in the D2 size. That cold, dry snow became saturated and wet loose avalanches were the theme of the week. Another observation from Monday highlighted natural, wet loose avalanches also D2 in size. The warmup peaked on Wednesday with temperatures in the mountains reaching the mid to upper 50s and McCall airport recorded 60 (tying the record high temp). Melt-water production was in full swing saturating the snowpack 1-2 meters (3-6 feet) deep in some places. Wet avalanche problems have remained the concern heading into the weekend. Thursday-Friday, temperatures cooled and we saw a return to more wintry weather. Although melt-water percolating into the snowpack has slowed since mid-week, the upper 1-3 feet of the snowpack remain wet-moist. This saturated snowpack will take a few days to "lock up" with colder temperatures. Wet, mushy snow could linger a bit longer at lower elevations. During the past 7 days, SNOTEL sites recorded 10-20" of snow loss from melting and settlement. Some of these sites recorded an increase of 1-2" SWE (1-2" of melt water flowed down through the snowpack). While other lower elevation sites recorded 1-3" of SWE loss (water leaving the snowpack and into the river).

Want to support your local avalanche forecast? Submit an observation. Submitting an observation on our website is a great way to help forecasters gather more information and improve avalanche forecasts.

Understanding Avalanche Safety Preparedness – 5-Minute Survey for Motorized Users

Eastern Oregon University is conducting a survey to better understand avalanche safety preparedness among motorized backcountry users like you. Your feedback will help us learn more about who is purchasing and practicing with avalanche rescue gear (beacon, probe, shovel) and participating in avalanche education—and why some riders aren’t.  The survey is confidential and anonymous. Go to the survey here.