Quick report
Overflight of terrain south of Portage revealed some recent very large avalanches failing at or near the ground (from this Tuesday we believe). Numerous avalanches on W, SW,E,SE and N were witnessed failing on what is almost certainly the old basal facets at the bottom of the snowpack. Several of the crowns exceeded a thousand feet in width with crowns estimated more than 10 feet deep in some of the largest slides. Although common wisdom lends towards avoiding thinner steep rocky areas, the area where these were witnessed tend to be the deepest snowpack in the region (around Portage and the PWS). Therefore the inverse may be currently be also true, in that the basal facets are just temporarily dormant in much of the forecast region just waiting for slightly more load to become active again. The recency of the natural activity is abnormal given the modest load from this week. Earlier this season the winds spared much of the Placer/Skookum zone (compared to other zones) and it may behave differently than Turnagain and other areas of the forecast zones. There is no way to forecast this type of full depth activity at this point, so hopefully it is limited to this particular region moving forward but its worth closely watching for any natural activity failing anywhere in the forecast area on this basal facets the rest of the season as that will likely be the only indicator of use to a backcountry user. These types of avalanches witnessed would almost certainly be unsurvivable, so if you see any recent activity of this nature you probably want to avoid being in that zone for an extended period of time.
Avalanche
Overflight of terrain south of Portage revealed some recent very large avalanches failing at or near the ground (from this Tuesday we believe). Numerous avalanches on W, SW,E,SE and N were witnessed failing on what is almost certainly the old basal facets at the bottom of the snowpack. Several of the crowns exceeded a thousand feet in width with crowns estimated more than 10 feet deep in some of the largest slides.