Skiers trigger avalanche south of Nelson BC… – Featured Photo Coralie Nairn, Vernon SAR
TMTV.NET Nelson BC Canada – Published @ 1:50PM Thursday Jan 4, 2018 – There has been another Avalanche that has caused injuries in the West Kootenay. This is the second to occur within 5 days. One happened on the afternoon of Dec 31, the other occurring Thursday.
RCMP, Nelson Search and Rescue, Whitewater Ski Resort’s Snow Safety staff along with BC Paramedics attended the scene Thursday afternoon and set set up a staging area at the Whitewater Ski Resort south of the West Kootenay city of Nelson BC.
Updated Jan 7, 2018 – Whitewater Ski Resort Release – On January 4, 2018 at 12:41 pm a member of the public informed Whitewater Ski Resort’s Snow Safety staff of a possible avalanche incident in the surrounding backcountry area known as Evening Ridge. Whitewater’s Snow Safety team investigated and then initiated an organized response with Nelson Search and Rescue (NSAR) supporting the rescue efforts.
The avalanche occurred on a steep open slope that the group had ski toured to from the access road of the resort. One (1) member of a party of three (3) men dropped into the start zone of a face that triggered a size 3 avalanche which carried the one skier down the slope approximately 300 m until he was hung up in some small trees. The injured skier, a 30 year old male from France, was reached by rescuers where they proceeded to stabilize and package the victim for transportation from the scene. The skier was then lowered down the avalanche path by rescuers to a safer area and extracted before dark off the slope by a rescue winch helicopter from Vernon. The injured person was flown to Trail airport and rushed to the hospital where he sustained serious life threatening injuries.
On the date of the incident Avalanche Canada was rating the backcountry hazard as Considerable at tree line elevation, which is where the incident occurred. A Considerable hazard rating means dangerous avalanche conditions exist and conservative decision making is essential. If traveling in the backcountry it is always strongly recommended that skiers and snowboarders check avalanche.ca for updated avalanche danger ratings and warnings. With conditions rapidly changing due to recent warming, added snow and increased wind has added stress to the deeper weaknesses in the snowpack, thus increasing the hazards in the backcountry.
Avalanche Summary from Avalanche.ca
On Thursday we received a preliminary report of an avalanche accident in the Evening Ridge area outside of Nelson. No details about the size or failure plane are known at this time.
On Monday another avalanche failing on the mid-December interface was triggered remotely from 10 m away as a skier approached a rocky outcropping on an east/southeast facing feature around 1900 m, MIN report with photos here. A skier also triggered a small storm slab on a west facing feature around 2200 m Monday which was suspected to have failed on the late December surface hoar.
On Sunday a skier was involved in an avalanche on an east facing treeline feature at Kootenay Pass. A recent crown profile has shown that this avalanche failed on the late November crust/facet interface.
On Saturday we received two reports of large avalanches failing on the mid-December interface. The first was initiated by explosive control work, the size 2.5 avalanche ran on a 35 to 40 degree slope that was southeast through southwest facing at treeline. The second avalanche was a size 3.0 that released naturally on a 30 degree east facing slope between 1900 and 1400 m. This crown was up to 75 cm in depth.
Snowpack Summary from Avalanche.ca
Last week two successive storms produced 25 to 50 cm of low density storm snow that was accompanied by moderate to strong winds out of the east, southeast, south and southwest. The new snow overlies the late December surface hoar which is 3 to 5 mm in size. We don’t know much about the distribution of this weak layer yet. Warming alpine temperatures on Tuesday began to moisten the snow surface on steep southerly aspects. Surface hoar has started to blossom on the surface recently too.
Between 60 and 100 cm below the surface you’ll find the December 15th interface which consists of a melt-freeze crust on steep, solar, higher elevation slopes and well-developed surface hoar which seems most pronounced in sheltered terrain at and below treeline. The overlying slab is now deep and is gaining cohesion. This interface has hit the tipping point for human triggering as evidenced by recent avalanche activity listed above.
Two laminated crusts created by twin rain events in late November lay just below the December 15th interface, 60 to 100 cm below the surface. There may be facets above the uppermost crust and sandwiched between the two crusts.
Weather Forecast from Avalanche.ca
A mild storm track is expected this weekend, which should allow for a bit of a warm up at valley bottom.
FRIDAY: Overcast, freezing level around 500 m, light to moderate southwest wind, 1 to 3 mm of precipitation expected.
SATURDAY: Overcast, freezing level around 500 m, light to moderate southwest wind, 1 to 4 mm of precipitation expected.
SUNDAY: Overcast, freezing level around 500 m, light west/northwest wind, trace of precipitation expected.
More details can be found on the Mountain Weather Forecast.
— TMTV BCTV Kootenays (@TMTVBCTV) January 4, 2018