Avalanche Forecast
Issued: Feb 6th, 2018 4:12PM
The alpine rating is Storm Slabs and Cornices.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Moderate - Intensity of incoming weather systems is uncertain on Wednesday
Weather Forecast
The Coquihalla can expect 5-15 cm overnight Tuesday accompanied by strong westerly winds. Less expected on the Duffy.Wednesday: 5-10 cm of new snow through the day with another 15-25 cm overnight Thursday. Strong southwest winds at ridgetop elevations. Freezing levels near 1200 m. Thursday: Another 10-15 cm expected tapering off throughout the day. Ridgetop winds light with strong gusts from the southwest. Freezing levels near 1400 m.Friday: A mix of sun and cloud. Alpine temperatures near -12 with a high of -4. Light-moderate ridgetop winds from the northeast and freezing levels at valley bottom.
Avalanche Summary
On Monday, no new avalanches were reported. Evidence remains of last weeks widespread avalanche cycle up to size 3.5 from alpine features, below rock bands and thin snowpack areas. Forecast new snow and wind will likely build new storm slab problems Wednesday afternoon into Thursday.
Snowpack Summary
Recent snowfall totals are highly variable. In the south, up to 40cm of snow fell in the alpine over the past three days, while tree line elevations saw 10-20cm. In the north, new snow totals were 15-20cm in the alpine, and rapidly decreasing below 1800m.In the alpine, winds were moderate to strong from the south / east (Coquihalla) and moderate from the south / west (Duffey zone), creating fresh wind slabs in exposed downwind (lee) terrain. At lower treeline and below, warm temperatures (and rain in many locations) have created heavy snow and tough riding conditions.The new snow adds to the 80-150cm of snow that fell during the last few weeks of January. These series of storms were accompanied by strong to extreme winds which resulted in extensive scouring and impressive cornice growth in upper elevation terrain. These accumulations sit on crusts from early and mid-January which generally show signs of bonding to the overlying snow; however, a week ago they were sensitive to human triggering. With forecast snowfall and strong winds this deeper instability may wake up initiation large and destructive avalanches.
Problems
Storm Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 7th, 2018 2:00PM