Some areas may not have seen enough precipitation to "clean out" buried persistent weaknesses. Proceed cautiously until we have a clearer picture of how conditions have changed.
Summary
Confidence
Moderate - Freezing levels are uncertain
Weather Forecast
Tonight and Friday: Rain or snow ending in the morning (10-15 mm), then cloudy with sunny breaks. The freezing level dips from 1800 m to 1400 m. Winds are moderate S easing to light from the SW. Saturday: Cloudy with sunny breaks. The freezing level is around 1000-1200 m and winds remain light from the W-SW. Sunday: Cloudy with sunny breaks. The freezing level is around 800-1000 m and winds are light from the SW.
Avalanche Summary
We will have to wait a day or two to determine how extensive the avalanche cycle on Thursday was. My guess is that we saw widespread activity at all elevations with slides up to at least size 3. Natural activity should taper off heading into the weekend. Hopefully the buried surface hoar problems were cleaned out, but I would treat any slope that did not release as being suspect, especially at treeline.
Snowpack Summary
The upper snowpack may look quite different after Thursday's storm. Expect dense new wind and storm slabs, and fresh cornice growth at upper elevations. Heavy loading from snow (and potentially rain) may have flushed-out the mid- and early-January surface hoar/facet layers that were initially buried 30-40 cm deep. However, don't rule these layers out right away. It may still be possible to trigger shallow slopes that did not release naturally. Rain has probably saturated the upper snowpack on lower elevation slopes (below 1500-1800 m), especially in the south of the region. The mid and lower snowpack is generally strong, with the exception of shallower snowpack areas that may be more faceted.
pmarshall,
Avalanche Canada
