Due to limited field observations, the likelihood of triggering large avalanches on persistent weak layers in this region is uncertain.
Conservative decision-making is recommended.
Smaller wind slabs have likely formed from recent winds. Some light snow Friday with wind will add to this problem. We are uncertain about how prevalent these are in Little Yoho due to limited field observations.
A 60-100 cm slab overlies mid-pack facets. We have limited observations from this zone since the storm, but this layer seems less reactive in Little Yoho than in areas further east. Caution is advised as this layer needs time to stabilize: avoid start zones and be very wary of overhead hazard.
No new avalanches were observed in Little Yoho. On Wednesday, avalanche control on Mont Field and Dennis produced avalanches to size 2.5 on the persistent layer.
Over the past two weeks, many large avalanches have been seen in adjacent areas to the East of the divide. See Banff bulletin for details.
At treeline, 70-100 cm of snow overlies the Jan. 30 / Feb. 22 drought layers, which consist of 20-30 cm of weak faceted crystals. These layers have been reactive in tests and recent avalanches. Average snowpack depth at treeline is ~200 cm.
In this thicker snowpack region, the facet/depth hoar basal layer is less prominent than it is East of the divide but likely exists in thin areas. Expect a surface crust on solar aspects at treeline and below.
Friday - 5 cm of snow, moderate winds, and mainly cloudy. Treeline high temperatures around -4C.
Saturday - Trace amounts of snow and light to moderate winds.
See below for more details
