Jan 2, 2025 Conditions Report with Mitch Sulkers
Snowfall, Wind, and Weather…
We have some very fine backcountry skiing in the Sea-to-Sky as I write, with the very best skiing tending to be in protected areas, especially below treeline. For the deepest turns, we found tree skiing in the Whistler area provided up to 50cm of ski penetration in zones from 1720m and up, even on solar aspects. In the absence of a big storm in the previous week and with more normal winter temperatures, the storm snow over the December 21 melt-freeze crust is fully right side up in that zone, with a good bond to the late December crust layer and some light, faceted crystals at the top of the snowpack.
In the alpine, the wind has had more effect, with exposed aspects and features somewhat stiffer on top, and soft to hard windslabs in areas where wind accelerated, especially near ridgecrests. In the lee of these features, even in the alpine, there was still good riding to be had, and the couloir hunters have been starting to head out to get their alpine gems.
Looking forward into this week, three things are on my mind: predicted snowfall amounts, wind, and weather–specifically warmer alpine temperatures. Here’s what I’ll be looking out for:
Snowfall:
Forecast amounts for early in this week have been quite low, with Saturday afternoon, early Sunday really the only producer as of early Saturday morning forecasts. From seven to 12 cms are predicted at 1800m in the Whistler area, with significantly more in the Squamish zone and less in the Cayoosh. Freezing levels remain low during this storm, so it will be low density new snow.
By itself, this amount of new snow in the Whistler area will not be enough to tip the stability scales at treeline and below treeline, which is good news. Expect an increase in the quality of the riding in these zones, especially below treeline.
Wind:
Wind however, will be an important factor to consider. After this weekend’s storm, wind is forecast to be low speed. It is during the storm that we may see wind gusts over 40kph, enough to start moving low density snow and redistributing it. This is when up to 12cms of fresh could increase avalanche danger, especially at treeline and in the alpine. If winds hit 60 or more kph during the storm, windslabs three to five times the depth of the total snowfall may be formed in lee regions, especially in the alpine.
It will be important to keep track of wind speeds and direction during the storm, as this will indicate where the most problematic areas may be when the sun starts to poke out on Sunday. Even on Thursday and Friday, winds at treeline and alpine were continuing to redistribute low density snow at treeline and alpine, forming new soft slabs up to 20cm thick in the lower alpine.
Weather (especially clear skies and temperature):
Currently, once the weekend storm passes, we can expect the re-emergence of the sun until possible late in the week. This coincides with a warmer SW flow that will begin to raise freezing levels, with some models suggesting a freezing level of 2300m or more by Thursday.
Where this temperature rise is likely to have the greatest effect is on steeper southerly aspects, at all elevation bands. Steeper slopes exposed to direct sunlight, even in January, can show warming from the winter sun, and areas with spaced trees and forecast low wind speeds may warm up even more. Alpine areas with low snow cover over dark rock will also feel the effect more.
If you notice the surface snow becoming more dense or sticky on these aspects, it is likely the stability is deteriorating and you should be on your escape plan. Areas that might most significantly be affected by these factors would be areas like the Cake Hole on Whistler, or Cowboy Ridge in the late afternoon. Polar aspects are much less likely to be affected in the short term, but these will also be the areas more likely to have formed new windslabs.
Final thoughts:
The considerations above are most applicable to the Whistler area. Consider this before making your plans for your backcountry tour, and follow the weather and snow condition reports carefully while planning your trip.
In the short term, Avalanche Canada is recommending a number of important factors to consider in its “Terrain and Travel Advice” for the Sea to Sky Corridor:
Watch for newly formed and reactive windslabs are you move into wind-affected terrain
Recent wind has varied in direction, so watch for windslabs on all aspects (especially at treeline and alpine levels)
Closely monitor how the new snow is bonding to the old surfaces
The best riding will be on slopes that have soft snow without slab properties
There is good riding to be had in the backcountry. Keeping the above factors in mind should help with planning and executing a good and safe backcountry trip.
