Avalanche Canada is warning of high and even extreme avalanche risks in the Alberta Rockies and parts of the B.C. Interior heading into the weekend.

The non-profit organization says a series of atmospheric rivers are drenching mountain ranges as they pass through, potentially weakening snowpacks.

The warnings range from a moderate risk to the highest level — extreme — in some areas on Thursday or Friday.

“We’ll probably see widespread avalanche activity in areas where the weather is most intense, or in areas where there’s persistent slab problems,” said Tyson Rettie, a forecaster with Avalanche Canada.

Rettie says those avalanches could also be large in size, and may start at higher points then travel to low elevations, where snowshoers or cross-country skiers could be caught off guard.

“The message right now in those areas is to avoid avalanche terrain. And if you feel like you don’t have a keen eye for what is or isn’t avalanche terrain, then it may be appropriate not to go into the backcountry,” said Rettie.

There have been five avalanche deaths in B.C. so far this season and one in Alberta — a 15-year-old skier who died after an avalanche at Nakiska Ski Area.

Rettie says the risk is expected to remain through the weekend, before improving as rains taper off Saturday into Sunday.

Near the B.C.-Alberta border, Highway 93 is closed at the western boundary of Kootenay National Park through Saturday due to an increased avalanche risk, according to DriveBC.

Jasper National Park posted on social media Monday that the Icefields Parkway will be closed between Athabasca Falls and Saskatchewan River Crossing for avalanche control activities. The earliest the roadway might reopen would be late Friday, the post said.