Human triggered avalanches remain likely Wednesday, especially in steep wind-loaded terrain above treeline. Choose conservative lines and watch for clues of instability.
Summary
Confidence
Low - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
The parade of Pacific storms will continue across southern B.C for the next several days, keeping alpine snow packs building through Thursday. The next system on Wednesday will be weak and affect mainly the south coast. Thursday's storm will be the main event of the week and feature moderate to heavy snow for the south coast alpine and much of the interior. The biggest snow accumulations this week will be over the South Coast and Interior Ranges.WEDNESDAY: Overcast, freezing level holding at 800 m, moderate northwest wind, 1 to 3 cm of snow possible. WEDNESDAY NIGHT: Freezing level at 1000 m, moderate south wind, 25 to 40 cm of snow possible.THURSDAY: Overcast, freezing around 1100 m, strong west/southwest wind, 15 to 30 cm of snow possible.FRIDAY: Overcast, freezing level around 900 m, light variable wind, no snow expected.
Avalanche Summary
On Tuesday we received a report of a skier triggering a size 2.0 avalanche on the First Pump of Mount Seymour above the summer snowshoe trail. This is presumed to be the south facing slab at 1300 m, but this is not confirmed. On Monday storm slabs were sensitive to skier triggering to size 1.0 on northwest through southeast facing features with crowns 10 to 15 cm in depth.
Snowpack Summary
In the last 48 hours the North Shore Mountains have received about 85 mm of rain, and approximately 20 cm of snow with a rapidly fluctuating freezing level. 10 to 20 cm of rain soaked snow now rests on the rain crust that formed Monday January 8th. Below the January 8th crust there is 15 to 30 cm of well settled rain soaked snow, that snow sits on the January 7th melt/freeze crust. The January 8th crust may not be present in the Alpine where temperatures are thought to have stayed cooler over the last few days. Significantly more storm snow is likely present in the Alpine, but we have few observations from that elevation band.
Check out this great MIN report for an idea of current alpine conditions. Approximately 50 to 100 cm of moist snow are between the surface and a few prominent melt-freeze crusts that were buried mid-December, these crust layers have been reported to be bonding to the snow above and below. The snowpack depth at 1000 m is about 150 cm and many early season hazards are still present.
ghelgeson,
Avalanche Canada
