Dig down and investigate the bond between the recent storm snow and old surface snow before committing to big terrain. Be mindful of reactive wind slabs as you move around ridge features and wind-loaded terrain.
West-southwesterly wind has redistributed the recent storm snow. Use caution around steep ridge features and immediate lee and cross-loaded terrain.
20-40 cm snowfall over the weekend has developed as a slab. In more sheltered terrain this slab overlies a reactive layer of surface hoar which could make it touchier than expected, especially in the trees. Solar input could make this slab more reactive, don't lower your guard as the sun comes out.
MONDAY NIGHT: Partly cloudy. Alpine low temperature -12 C. Northwest wind 20-30 km/hr.
TUESDAY: Mix of sun and cloud. Alpine high temperature -3 C. North-northwest wind 15-25 km/hr
WEDNESDAY: Sunny. Alpine high temperature -2 C. Northwest wind 15-35 km/hr.
THURSDAY: Mostly sunny. Alpine high temperature -7 C. Southwest wind 10-15 km/hr.
This past weekend a reactive storm slab developed from 20-40 cm fresh snow, with higher snowfall amounts favoring the eastern part of the forecast region.
On Saturday, storm and wind slab avalanches size 1-1.5 were triggered by skiers, along with loose dry sluffing in steep terrain. In sheltered terrain, avalanches failed on a reactive layer of surface hoar buried by the storm snow. Overnight Saturday and into Sunday, the reactive storm slab produced a size 1-2 natural avalanche cycle.
Through Sunday, skier traffic and explosives continued to trigger size 1-2 avalanches. Storm slab avalanches were reported at treeline and below, with many reports on northeast to northwest aspects; a layer of surface hoar 20-40 cm is the likely culprit. At treeline and above, naturally failing and skier triggered wind slab avalanches were observed on south and east aspects.
20-40 cm new snow over the weekend covered a variety of surfaces: hard wind slabs around ridgetops and northerly alpine features, soft slabs and 10-15 cm of lower density snow in sheltered terrain, a thin sun crust on solar aspects, and scoured features in exposed terrain. A reactive layer of surface hoar has been the weak layer in many recent storm slab avalanches around treeline and below. In the alpine west-southwesterly winds have developed reactive windslabs with the touchiest deposits in lee-ward and cross-loaded terrain.
A thick rain crust to mountain top sits 10-40 cm of below the surface in the east of the region and 40-100 cm in the west. Reports suggest the bond is improving, and the midpack below the crust is wll settled. Weak facet/crust layers near the base of the snowpack have not been an active avalanche problem recently.
