Avalanche Canada is urging people to stay out of the backcountry as a powerful weather system drives high to extreme avalanche danger across much of the Alberta Rockies and the B.C. Interior.

Forecasters are asking people to avoid the backcountry entirely unless they are in a non-avalanche terrain or at a controlled ski hill.

Tyson Rettie, a forecaster with Avalanche Canada, says the combination of “extreme winds, heavy precipitation, and quite high freezing levels” is rapidly weakening the snowpack across all southern mountain regions in both provinces.

Officials warn that the risk is now very high to extreme, with widespread and potentially large avalanches likely. Some could run farther than usual and reach lower elevations, posing risks even to people who believe they are travelling outside avalanche terrain.

“People cross‑country skiing or snowshoeing could be travelling at low elevations which may give them the impression they are not in avalanche terrain, but you still have large steep slopes above you,” Rettie said.

Parks Canada has closed Highway 93 North and South, including parts of the Icefields Parkway, due to dangerous snow slides. Reopening is expected Saturday, depending on conditions.

Traffic is being rerouted through Yoho National Park to Golden, B.C.

Rettie says the scale of the closures reflects the intensity of this weather event.

“While atmospheric rivers themselves are not uncommon or unheard of, having one this late in the season, anecdotally, is uncommon,” he says.

Officials expect the avalanche hazard to begin easing late Saturday into Sunday as the weather system moves out and temperatures stabilize.

Until then, Parks Canada is reminding visitors to stay on marked trails, obey avalanche signage, and check DriveBC and Alberta 511 for the latest travel information.