Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 2–3
Recent Avalanches: On Saturday, a large avalanche was triggered by a snowmachiner in Warmup Bowl on the backside of Seattle Ridge. The snowmachiner was caught, fully buried, and did not survive. See the video to the right for a description and read more info here. On Friday, there were 4 human-triggered avalanches reported on the backside of Seattle Ridge with no one being caught.
It has been 25 days since our danger rating has dropped below considerable in Turnagain Pass despite many days of calm weather. The problem layer of buried surface hoar that is 1 to 3' deep across forecast zones is unusually dangerous because it is allowing many tracks on a slope before releasing into a large avalanche. It is also difficult to assess where this might occur because our snowpits are giving us stable results with large human-triggered avalanches occurring within 50 to 100' of these stable results. We don't trust this snowpack and the only way to avoid this problem is to stick to low angle slopes with nothing steep above.
There is a noticable lack of avalanche activity on the non-motorized side of Turnagain Pass. With the exception of a few storm slabs on the south side of Cornbiscuit on March 18, March 13 was the last day natural and human-triggered avalanches were reported on the east side of the highway. These occurred in Lynx Creek on the south end of Turnagain Pass. On March 9 a large human-triggered avalanche occurred on Eddies. We don't know exactly why there are less avalanches occurring on the non-motorized side because the layer of buried surface hoar exists across the zone. It could be that there is less traffic on the slopes on the east side or something else, but either way we don't trust the snowpack anywhere in Turnagain Pass. The weight of a person could trigger one of these large and dangerous avalanches if we find the wrong spot.
