We anticipate an avalanche cycle on Tuesday and Wednesday as freezing levels rise to 2500 - 3000 m and the sun comes out on Wednesday. This, plus 5-10 cm of snow and rain to treeline on Tuesday will increase the likelihood of avalanches. Avoid avalanche terrain on both days and expect better conditions starting Thursday as it cools.
Windslabs up to 40 cm deep have been releasing easily from ski cuts, with one report of a skier going for a ride in a size 1.5 that broke 2 meters above them. Expect this problem in the somewhat predictable, leeward and cross-loaded areas at treeline and above.
A 60-100 cm slab overlies mid-pack facets and our limited snowpack tests (Mt. Field only) indicate a generally strong snowpack close to 200 cm deep at treeline. We no observations from the alpine and high uncertainty because our observations are limited in this area.
No new observations or reports of fresh avalanches in this area, but our information is limited to valley bottom binoculars and no field reports. On Saturday, guides working in the area indicate several large avalanches releasing in steep, wind-loaded terrain (up to size 3).
Over the past few days, 15-20 cm of moist (heavy) new snow has been blown into windslabs up to 40 cm deep in leeward areas at treeline and in the alpine. This adds to the dense slab, 70-100 cm thick, overlying a 20-30 layer of faceted crystals. We have no recent snowpack tests to confirm the strength of this layer in Yoho, but in thicker snowpack regions such as here, the facet/depth hoar basal layer is less prominent than it is east of the divide.
Warm air continues to invade the region on Tuesday, accompanied by 5-10 cm of snow which may turn to rain on Tuesday afternoon. Valley bottom temperatures in Lake Louise will hit +10 on Tuesday and +13 on Wednesday when the sun comes out. Freezing levels will peak on Wednesday between 2500 - 3000 meters.
