The snowpack needs time to adust to the 50+ cm of snow left by a series of warm storms. Seek out simple terrain and avoid overhead hazard Tuesday.
It's been a stormy period and Monday's warm storm has produced almost 15 cm as of 4:00 PM Monday. This makes for a little over 45 cm since Friday evening which has been accompanied by strong southwest wind. The upper snowpack will need a bit of time to adjust to this new load, but incoming cool temperatures should help with that process in the coming days.
After a series of warm storms we’re entering a clearing trend that extends for the foreseeable future.
MONDAY NIGHT: Freezing level may rise to 1100 m or so, but should stay closer to valley bottom, strong to extreme south/southwest wind, 5 to 15 cm of snow expected.
TUESDAY: Broken cloud cover, freezing level at valley bottom, moderate to strong west wind, 1 to 5 cm of snow possible.
WEDNESDAY: A few clouds at dawn building to broken cloud cover by sunset, freezing level at valley bottom, moderate west/southwest wind, no snow expected.
THURSDAY: A few clouds in the morning clearing by lunch, freezing level at valley bottom, light northwest wind, no snow expected.
We got some good MIN posts this weekend from the Wheaton Valley where one group found some older avalanche activity and another where skiers found some shooting cracks in the new snow.
Our field team took a quick look around Saturday while the road was closed. They found evidence of a natural avalanche cycle to size 1.5 with crowns up to 30 cm in depth. Interestingly, this kind of activity was found in upper treeline and alpine terrain. More details here.
The avalanches that impacted the highway Friday night were reported as four size 2 avalanches that started high and ran full path. These were likely wind fuelled storm slab avalanches.
On Thursday a skier triggered avalanche was reported from the "Eggnog gully" which overlooks Tutshi lake to the south. The soft slab was 50 cm in depth, 10 m across and ran 10 to 15 m down into dense fir trees. The skier was not caught in the avalanche. The avalanche likely ran on surface hoar.
The rather warm storm produced just over 45 cm of snow between Friday evening and Monday afternoon. This storm has been accompanied by plenty of southwest wind. One last pulse of warm storm is expected Monday night.
Around Log Cabin, around 70 cm of snow may overlie a layer of surface hoar. This layer was the culprit of avalanche activity during the week of Monday, January 4th. This layer has not been reported elsewhere in the region.
A buried crust from early December can be found 50-130 cm below the surface, but most reports suggest the snow is well-bonded to it.
The lower snowpack is strong around White Pass, but there is potential for a generally thinner and weaker snowpack structure to exist in inland areas, such as the Wheaton Valley.
