Avalanche Forecast
Issued: Jan 20th, 2019 8:00AM
The alpine rating is Storm Slabs.
, the treeline rating is , and the below treeline rating is Known problems include Watch for storm slab as you venture into exposed treeline and alpine terrain.
Summary
Weather Forecast
Cloudy with sunny periods, light winds and an alpine high of -9C forecast today. Monday looks to be very similar. Flurries are forecast for Tuesday Wednesday. If prolonged sunny periods occur today expect surface layers on steeper solar aspects to start sloughing.
Snowpack Summary
25cm of storm snow in the last 48hrs mod South wind yesterday. Limited storm slab development observed on field trips yesterday but our obs limited to TL and below. Storm snow will hide underlying wind slab in the alpine, a crust on steep solar aspects, and large surface hoar in sheltered areas. The Nov 21 persistent weak layer is down ~180cm.
Avalanche Summary
A natural avalanche cycle occurred in the highway corridor east of Rogers Pass mid day yesterday coinciding with a gusty strong S winds. Slides were up to size 3 and ran to 3/4 runout. One size 2.5 slide recorded off of Mt Smart in the west end of the forecast area.
Confidence
Due to the number of field observations
Problems
Storm Slabs
A storm slab sits on top of the January 17th surface hoar layer and old windslab depending on location. TL field trips yesterday found it to be very soft. Wind effected areas at higher elevation are expected to be more sensitive with a denser slab.
Dig down to find and test weak layers before committing to a line.Use caution in wind effected areas where storm slabs may be more sensitive to triggering.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 21st, 2019 8:00AM