A shot of fresh snow and wind Sunday night will keep the danger elevated Monday. Give corniced slopes a miss as temperatures begin to warm Monday afternoon.
Summary
Confidence
Low - Due to the number of field observations
Weather Forecast
The South Rockies will see a relatively modest shot of snow and wind Sunday night before the atmosphere begins to shift to a more classical spring pattern. This should result in a strong diurnal temperature swing with very little in the way of precipitation expected for the forecast period. SUNDAY NIGHT: Freezing level around 1800 m at sunset, steadily lowering to valley bottom overnight, 2 to 10 cm of snow, moderate to strong southwest winds. MONDAY: Freezing level starting at valley bottom rising to 1400 m, 1 to 4 cm of snow, moderate west / southwest winds. TUESDAY: Freezing level starting at valley bottom, rising to 1600 m, no significant precipitation expected, moderate west / northwest winds. WEDNESDAY: Freezing level starting near valley bottom, rising to 1600 m, no significant precipitation, light west / northwest winds.
Avalanche Summary
On Saturday a few natural cornice failures to size 2 were observed in extreme terrain. On Friday a few different very large avalanches (to size 3.5) were observed that failed naturally on southerly facing alpine features. These avalanches were likely triggered by falling chunks of cornice impacting thin snowpack areas in the far north of the region. Debris ran down the track well into the below treeline vegetation band. Natural cornice failures were also reported Friday to size 1.5. Reports from Thursday are limited but include skier-controlled size 1 wind slab avalanches. Natural wind and storm slab avalanche activity was expected on Thursday in response to heavy loading from snow, wind and rain.
Snowpack Summary
Approximately 25 cm of fresh snow is unlikely to be bonding well to a widespread supportive crust, with the most recent snow-line reaching 1800 m in the Elk Valley. In exposed terrain, widespread and potentially touchy wind slabs likely lurk below ridge-crests, behind terrain breaks and in chutes. Deeper in the snowpack, recent tests gave very easy sudden collapse results down 80 cm on a southeast aspect at 1850 m on the deep persistent facet/crust weakness that was buried early December. Watch this weakness with extreme warming from sun-exposure, or warming/loading from rain. Cornices are also reported to be huge and weak. Check out the latest SoRo field team video on Instagram: @avcansouthrockies
ghelgeson,
Avalanche Canada
