Avalanche Forecast

Fair - Freezing levels are uncertain on Wednesday

The Purcells have received around 30cm of snow on the storm boards in the North & 20 - 30cm in the South of the region. Snow is expected to continue through the day Monday with a daytime total of 12cm. The region should see another 5cm Monday night, bringing the storm total to aprox. 50cm. Tuesday looks to be clear and cold as freezing levels return to the surface. Winds should be L out of the N/NE @ 2000m Tuesday. Temperatures warm Wednesday as warm air floods the region, we expect a freezing level around 1700 on Wednesday. The warming continues Thursday, the freezing level starts near 1000m, the current model runs show the precip climbing to 2400m in the afternoon.

We received reports late in the day that indicate a large natural avalanche cycle was in progress Monday. A sledder triggered a size 3 avalanche in the Quartz Creek area and while the machine is reportedly totaled, the rider is okay. Control work in the Dogtooth's Sunday produced avalanches to size 2.5. The buried surface hoar continued to preform, numerous soft slab avalanches were remoted by skiers to size 2. One operation in the Northern Purcells reported an avalanche cycle involving wet snow at low elevations which produced avalanches to size 3. In the southern portion of the region Natural and sled triggered avalanches to size 2.5 were reported. With all the new snow & wind I suspect there was widespread natural activity Monday. Visibility was limited, so, we probably won't know the extent of the action until skies clear Tuesday.There are two great observations from professionals working in the region recently. The first one can be found on the MCR, it talks about the widespread & sensitive nature of the SH in the Northern Purcells. You can start here and work your way into the March observations: http://www.acmg.ca/mcr/archives.asp The other is in the form of a youtube video which also deals with the surface hoar, highlighting the potential for remote triggering and large propagations when this layer fails. Check out the shooting cracks in the video. Wild!: http://www.youtube.com/watch?v=UmSJkS3SSbA&feature=youtu.be One of our field tech's checked in after a personal hut trip in the Northern Purcells. He reports a touchy surface hoar buried down 40cm below the snow surface (before the Sun/Mon. storm) which is consistent with observations from the region.

30 cm of storm snow fell across the region during daylight hours Monday accompanied by winds out of the W/NW & W/SW at speeds capable of wind slab formation. Another 15cm are expected before skies clear Tuesday. A cohesive slab continues to settle over the mid-February surface hoar, which is now down 70 to 100 centimeters. Recent reports include whumpfing and cracking, and moderate but sudden compression test results. This persistent weakness is susceptible to remote triggering and has the ability to propagate in low angled terrain, and the overlying slab structure creates the potential for step-down avalanches. Basal facets have only been reactive on steep, shallow, and rocky slopes, but operators continue to monitor this layer in tests. Triggering this deep persistent weak layer is unlikely, but shallow snowpack areas or shallow weak areas adjacent to deeper wind loaded slopes are the most suspect locations.