Current Snowpack Synopsis
Pow, the story continues! February has delivered 165mm of snow water equivalent to the snowpack. Mt Fidelity’s weather station at 1905m is now reading 269cm for a height of snow. This past week, amidst a strong arctic outbreak, 61cm of storm snow has fallen, but there has been 68 cm of settlement in the height of snow.
What’s that mean? The upper and mid pack are continuing to settle and bond and are slowly bridging and squashing the November facets at the bottom of the snowpack.
61cm of recent storm snow has fallen in since midnight Feb 19, which was accompanied by moderate to strong S-SW flow and a three day period of northerly winds coupled with temperatures reaching -30. This recent storm snow overlies colder and lower density storm snow from early last week and wide spread wind effect (sastrugi in some parts of the alpine) that reached into exposed areas below tree line. On steep solar aspects a melt freeze crust exists down approximately 50-70cm.
The mid-pack is gaining strength and rounding with the continued precipitation and mild temperatures we’ve had recently. the January surface hoar layers are rounding, but can still be found in isolated areas down 1.5-2m.
However the November facets are still prominent at the base of the snowpack. The facets are showing signs of rounding, but there is still a considerable step in resistance between them and the overlying snow. The November facets are more pronounced in shallow rocky areas.
What’s been riding well
Over the past week there has been exceptional storm riding paired with a couple of fantastic, albeit COLD days of high pressure. Deep trail breaking continues to be a recent theme.
Strong northerly flow created wide spread wind effect in the alpine and into exposed areas below tree line. Heads up for buried sastrugi, it’s big and hard in some places.
Over the weekend with the recent storm inputs of precipitation and wind, sheltered areas at tree line and below have been the place to be. In exposed areas, storm slabs have been created in immediate lee features. Cracking, whumpfing and storm slabs reactive to skier traffic have been observed at tree line and in exposed tree line features.
The recent melt freeze crust on steep solar aspects is hardly felt under foot, except is steep sheltered below tree line features.
Recent Avalanche Activity
This has been a significant storm cycle and has produced natural avalanches to size 2.5 near Rogers Pass and explosive results to size 3.5. During the mid-week wind event, there were numerous deep persistent natural slab avalanches as well.
Today (Monday February 27th) there was a skier accidental size 2.5 on Bruins Ridge. The 12th skier who crossed the slope that links the ridge into 8812 Bowl triggered the avalanche and fortunately was able to self arrest when the slab fractured at his feet. This feature has avalanched twice before this season and this avalanche failed just above the ground on facets. The crown was roughly 100m wide and ranged from 45cm to 1.3m. The avalanche ran approximately 800m into the flats of 8812 Bowl. The previous 11 people who travelled on the skin track exercised good backcountry travel techniques by spacing out and crossing the slope one at a time. The unlucky number twelve skier apparently affected the weak layer more than everyone else and triggered the avalanche. There were no obvious signs of instability on this windward slope and pole probing revealed no significant steps in resistance. This feature has literally been crossed more than 1000 times this season.
One thing that should be mentioned about the photo above is backcountry etiquette. The first individual in the photo, the one closest to the top, chose to space out and travel one at a time across the slope after their partner had triggered the avalanche. The individual behind them, followed them closely across the slope, disregarding their wish to travel in a conservative manner. Please be a good neighbour out there folks. If a group chooses to space out or ski a slop one at a time, please respect their wishes and don’t crowd them.
Natural cornice failures have been observed recently too. The cold temps have continued to facet out the roots of cornices. The new snow coupled with the wind will have surely built fresh new additions to the cornices that will be fragile. Be vigilant and minimize your exposure to them
Sluffing in terrain over 35 degrees has been frequent with rider traffic.
Incoming weather and avalanche forecast
Snow. You gotta love it. As the cold air exits BC, we will see continued precipitation through Tuesday. Ridgetop winds winds will be in the moderate range from the southwest. By mid-week a low pressure system coming from the northwest will make its way towards the Columbia Mountains, bringing more snow! Keep it coming!
Cornices: Cornices have grown significantly in recent weeks and there have been numerous natural cornice failures that have resulted in avalanches up to size 3 in, or around Rogers Pass. Give them respect and a wide birth when you are travelling under them. Be cautious of solar input.
Storm slabs: Recent moderate to strong winds have caused storm slabs in exposed areas in alpine, tree line and below tree line features. There has been a natural cycle to size 2.5 over the weekend and these storm slabs will be reactive to rider traffic in the next few days. Watch out for reverse loading with the incoming northerly flow.
Dry Loose: Watch out for sluffing in terrain over 35 degrees. Sluffs have been running fast and far over the weekend.
Deep Persistent Slabs: The November facets are still very much a concern across the backcountry ski / snowboard industry in the Columbia Mountains. This past week exhibited continued natural avalanche activity failing on the November facets. They will need a bit of time to adjust to the new load that has been applied to them.
Be aware of overhead hazard.
The November facets are more pronounced in shallow, rocky features. Professionals are still maintaining a conservative mindset with this low probability/ high consequence avalanche problem.
Backcountry skiing and splitboarding are inherently dangerous activities. Decisions made about terrain in which you may choose to travel should be based on real time data you’ve collected firsthand, not on this report. Conditions in the mountains change rapidly, please be aware that things will probably have changed since this report was written.