Last day of warm windy weather ! Expect to see elevated temperatures and strong westerly winds at all elevations.
Continued snow transport has developed hard wind slabs, which are likely confined to shady alpine areas where dry snow still exists. While these slabs may be thin, they could be poorly bonded to the underlying snow, so be extra cautious in lee terrain and convex rolls.
A persistent slab problem formed by a crust down 80-150 cm has created a low likelihood, high consequence scenario that is difficult to forecast. There has been an increase of avalanche reports on this layer since the past weekend. Although the snowpack is slowly recovering from the last warm spell, it is uncertain how the recent warming/rain has affected the snowpack. In the meantime, avoid likely trigger spots such as steep, rocky slopes with a shallow or thin to thick snowpack.
SUNDAY: Mainly sunny, strong westerly winds, treeline high around -2 C, freezing level around to 1500 m .
MONDAY: Sunny periods, treeline high around 0 C, strong southwesterly wind, freezing level around 2000 m.
TUESDAY: Snow, 5-10 cm, treeline high around -8 C, moderate variable wind, freezing level lowering to valley bottom.
WEDNESDAY: Mainly sunny, treeline high around -12 C, strong southwesterly wind, freezing level at valley bottom.
No new avalanches were observed nor reported in the last 24 hours.
On Thursday, three very large avalanches were reported from this region. These avalanches failed on the early December crust and showed wide propagation. They occurred on southwest to southeast aspects and were naturally triggered in response to rising temperatures and solar radiation.
On Wednesday, one very large (size 3) and several smaller (size 1-2) wind slab avalanches were reported on mostly north to east aspects in the alpine. A large cornice fall (size 3) was also reported.
The broader area including the South Rockies and neighbouring regions has been experiencing a sporadic pattern of very large avalanches over the last couple of weeks.
Refreeze has created a melt-freeze crust up to 2000 m capping the recent snow which is settling fast and becoming dense due to warm temperatures. This snow sits on a variety of old surfaces, including soft snow in sheltered areas and wind slabs in exposed and open areas which formed over the past few days. Dry snow can still be found in the alpine but will likely be found as hard pockets of wind slabs.
The most notable layer of concern in the snowpack is a crust that was formed in early December and is now typically down 80-150 cm. In the neighbouring Lizard-Flathead region, three very large avalanches were reported on this layer on Jan 13. This layer has created a tricky low likelihood, high consequence scenario which is best managed through conservative terrain choices and disciplined backcountry travel techniques.
