BANFF – Some highways and roads through Banff, Yoho and Kootenay national parks are closed due to extreme avalanche danger and other potential hazards from heavy rain and snow..
Highways 93 South and North were both closed for avalanche control work on Wednesday (Dec. 1) and not expected to reopen until Thursday (Dec. 2). The access road to Sunshine Village in Banff National Park was also closed so Parks Canada could do avalanche control, forcing closure of Sunshine Village ski resort until possibly Friday.
In addition, RCMP also advised motorists to expect delays with a temporary planned closure of a roughly 16-km stretch of the Trans-Canada Highway in Yoho National Park near Field in both directions on Wednesday for avalanche control work.
"Travel to B.C. on Highway 1 is still significantly impacted and highway closures due to evolving weather conditions can happen with little notice," said Corporal Tammy Keibel, media relations officer for RCMP Southern Alberta district.
The avalanche rating is extreme in the alpine and at and below treeline throughout the area following an estimated 40 cms to 100 cms of snowfall during the storm that also brought heavy rain at lower elevations on Tuesday evening (Nov. 30).
Silvio Adamo, the Town of Banff’s director of emergency management, said the municipality was informed by the dispatch centre that roads including Highway 93 South and Highway 93 North have been closed, including the access roads to Sunshine Village and Takakkaw Falls this morning for avalanche control.
“There was a significant amount of rain mixed with heavy, wet snow, and so I believe Parks Canada is assessing all of the avalanche slopes currently and are making plans to ensure that the highways are safe for travel," he said.
The Trans-Canada Highway east of Golden, which has been closed for construction in Kicking Horse Pass, reopened Wednesday. Vehicles had diverted through Kootenay National Park on Highway 93 South and then Highway 95 from Radium to Golden and vice-versa.
Adamo said the Town of Banff will continue to get updated information from Parks Canada.
“We’ll continue to get information from Parks Canada and their highway crews to see how things are proceeding through the day," he said. "They are only anticipating a 24-hour closure at this time, but obviously, circumstances can change.”
According to Parks Canada’s avalanche bulletin issued just after 6 p.m. on Nov. 30, a significant storm would push avalanche danger ratings to extreme in the alpine, at treeline and below treeline on Wednesday.
“It will be best to enjoy the ski hills and avoid all avalanche terrain,” states the bulletin.
The first problem contributing to the avalanche hazard is the storm is expected to bring anywhere from 40 to 100 cms of new snow and strong winds, which will create storm slabs at all elevations.
The second concern is associated with a significant new snow load, meaning larger and more frequent avalanches are expected to occur on the basal crust and facets.
“These avalanches have potential to run a full path,” according to the bulletin.
“Be aware of the potential for full depth avalanches due to deeply buried week layers.”
The significant snowstorm will also create widespread loose snow slides at all elevations.
Rain and warm temperatures below 2,000 metres have the potential to create loose moist avalanches as well.
“Use extra caution on slopes if the snow is moist or wet,” advises Parks Canada. “Be careful of loose dry sluffing in steep, confined or exposed terrain.”
By Thursday, the avalanche forecast drops from extreme to high in the alpine and at treeline and considerable below treeline. On Friday, the forecast notes considerable avalanche hazard in the alpine and moderate at and below treeline.
On Tuesday night, Environment Canada issued a wind warning for an area that included Canmore, Exshaw and Kananaskis Country with strong, damaging westerly winds with gusts up to 110 km/h.
The howling winds tapered off Wednesday morning.