Avalanche Forecast
Issued: Feb 24th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
matt,
Avalanche Canada
Now isn't a great time to expose yourself to avalanche terrain. The hazard is rated as Considerable, but it's a blurry line right now. It could easily jump to High with our current weather pattern.
Summary
Confidence
Moderate
Avalanche Summary
The wind shift last night triggered a very widespread avalanche cycle. We lost track of counting after 18 separate observations. Common details:
Alpine and upper treeline, N-E aspects
Many started mid start zone or even in the track.
Up to sz3, with most around sz2
Appeared to be within the windslabs only. 30-50cm deep on average
Most ran to mid run out
wide and erratic propagations
Snowpack Summary
As expected the winds shifted last night with dramatic results. It appears that wind slabs formed almost immediately on aspects from N to SE. A very widespread avalanche cycle occurred overnight as these new slabs didn't bond well with the older surfaces. To be completely honest, we're not exactly sure why the avalanche cycle was so widespread, but we suspect it was a combination of a very quick change in wind direction and a spike in intensity. Other factors may be temperature change(inversion possibly), or even different snow characteristics from the two distinct storm waves. In any case, we do know without question that we have a widespread windslab problem in the alpine and treeline areas. These slabs will be touchy for some time and very prone to human triggering. In other snowpack news, below treeline and sheltered areas have 20-30cm of settled storm snow resting on facets and depth hoar. Sudden collapses have been noted while trail breaking.
Weather Summary
Saturday will see the temperatures rise to about -12 by early afternoon. So far it looks like it will be a slow, but steady temperature rise throughout the evening/night. Skies should be clear tomorrow with maybe a little bit of afternoon cloud. And how 'bout those winds? Glad you asked. They will stick with us and even increase a bit tomorrow. Ridge winds will be strong and treeline winds will be moderate, but with strong gusts. All from the west.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Be aware of the potential for surprisingly large avalanches due to deeply buried weak layers.
- Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
Problems
Wind Slabs
With our shifty winds, expect slabs on all aspects. These will continue to build into tomorrow.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
While this layer had a limited role in today's cycle, it remains on our radar as a problem. We know from watching other areas deal with it that its a very spontaneous and temperamental layer.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 25th, 2023 4:00PM
