The first Pineapple Express storm of the season — a blast of warm, moist, sub-tropical air and torrential rain — has hit B.C.'s South Coast, hiking the avalanche danger rating and setting up conditions that are perfect for a major snow slide.

For the first time this season, the Canadian Avalanche Centre has listed the risk as extreme in the alpine areas of the Sea-to-Sky region, and North and South Columbias, with a high risk posted in all other B.C. regions.

On the North Shore, both Cypress Mountain and Mount Seymour are closed Friday due to the weather.

Avalanche control work will be taking place this morning 26 kilometres west of Revelstoke on Highway 1 from 7:30 to 9:30 a.m. PT.

There is also avalanche control work on the Kootenay Pass on Highway 3 between 7 and 10 a.m. this morning.

Backcountry becoming more popular

While the avalanche danger ramps, more people than ever are heading  into the backcountry — deciding the rewards outweigh the risks.

Peter Smart, a ski guide with backcountry adventure company Extremely Canadian, regularly leads small groups of experienced skiers on adrenaline-filled trips.

"For decades I've been venturing off looking for that quiet spot of untouched powder and little bit of peace in the backcountry," he said.

While the exact number of people slipping under the ropes isn't known, sales of backcountry skis and boards have increased.

Gus Cormack of Prior Snowboards said ultra-light snowboards, which split in two and allow you to hike up steep slopes before boarding down, are selling particularly well.

"We've seen double digit growth in the backcountry ski and board category," he said.

But Cormack advises anyone heading to the backcountry to be prudent.

"I think that's really the most important piece of equipment people can get is good knowledge and ability to make good decisions when they are in the backcountry."

'A dramatic increase in responses'

The sheer number of newcomers heading to the backcountry has already put a strain on search and rescue crews.

Whistler search teams say their workload has doubled looking for people who get lost, hurt or misjudge the weather.

Anton Horvath of Whistler Blackcomb Resort said they've had 16 calls since January — twice the average number.

"There's been a dramatic increase in responses this year, over the last couple of months," he said. "It's getting out of control … people are heading out and don't have a clue where they are going."

So far,  the number of deaths or serious injuries from slides has been lower than average this winter, thanks mostly to the good weather, but this is traditionally the most dangerous time of year.

With files from CBC's Chris Brown, The Canadian Press