Avalanche Forecast
Issued: Feb 12th, 2020 1:00AM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
Bill Phipps,
VIAC
No new avalanches have been reported since Sunday Feb 9th.
Summary
Past Weather
Little to no new snow with temps ranging from just below 0 (overnight) to +8 (during the day).
Weather Forecast
Very light rain Wednesday changing to light to moderate snowfall Thursday through Friday with some wind transport expected.Wednesday - 0.1 to 2 mm of rain below 700-900 m, falling as small amounts of snow above. Winds light from the SW. Temps -2 to +2. Freezing levels 900-500 m. Thursday - 4 to 14 cm of new snow (lower amounts for East/Washington, moderate amounts for North/Cain, deepest for West/Strathcona). Winds moderate to strong S to SW. Temps 0 to -4. Freezing levels 900 to 1000 m. Friday - 1 to 8 cm of new snow. Winds light to moderate SW to NW. Temps -2 to -6. Freezing levels 700 to 900 m.
Terrain Advice
Avoid wind loaded open slopes at treeline and in the alpine as new snow Thursday into Friday will be transported, creating the potential for wind slab avalanche activity. The bond of these new slabs to the exposed old crust below will be very suspect.Keep an eye out for those tricky to see coming openings in the forest that create treeline like features at lower elevations, as wind slabs will be present once the snow and wind starts. Even though we are in winter, the below treeline snowpack is still shallow and many creeks, holes, rocks, roots and stumps are lurking on or just below the surface. Travel with care and slow down as you move into the lower elevation zones.
Snowpack Summary
Little to no new snow has fallen since the storm Friday Feb 7th into Sat Feb 8th. Over the past few days we have moved into a more spring like melt (during the day) freeze (overnight) cycle. Variable surface are present depending on aspect and elevation. Ridge tops are scoured to the old crust from the monsoon rain event on Jan 31, storm snow from last Fri Sat is still nice in wind sheltered non solar pockets, SE and NW alpine and open treeline elevations have pockets of wind slab from the Fri Sat storm and strong winds and finally.... Solar aspects treeline and below have a new thin melt freeze crust.
Snowpack Details
- Surface: Variable surface conditions from old wind slabs, exposed old crust, preserved snow to a new thin sun crust
- Upper: Fri Feb 7 to Sat Feb 8ths storm snow (bonding moderately well) over the thick and supportive Jan 31 rain crust
- Mid: Moist snow well settled with a few old crusts
- Lower: Well settled
Confidence
High - Weather models in agreement and good field data.
Problems
Wind Slabs
Lingering wind slabs from last Fri/Sat storm still exist in the alpine and open treeline. More new snow Thursday into Friday will add to and create new wind slabs in the alpine and treeline. These slabs will be on N-E-SE aspects and cross loaded features and have the potential to have a weak bond to the exposed crust zones they will fall on. Natural triggering is possible and human triggering is possible to likely from size 1 up to size 2 avalanches.
Likelihood
Expected Size
Valid until: Feb 13th, 2020 1:00AM
