VAIL — It’s just after 4 a.m. and light flakes are still falling, promising potentially soft turns — finally — on Vail Mountain.

Steve Semrow, halfway through his lonely shift at Vail Resorts, directs on-mountain cameras toward the snow stakes tucked into quiet corners of his company’s ski hills.

A little more than 3 inches has fallen at Vail, Beaver Creek and Breckenridge. Keystone, meanwhile, has less than a half inch, which qualifies as the teasing “trace.”

That’s not great news, but it isn’t bad either. The marketing machine can rev up now with pictures of fresh snow and begin delivering the message that has long been the backbone of Colorado’s $4 billion ski industry.

“The snow message is absolutely as important as it has ever been for us,” said Vail Mountain’s senior vice president and chief operating officer, Chris Jarnot.

What has changed is that everyone with a mobile phone can be a snow reporter — and everyone with a mobile phone or computer can be the instant recipient of the latest snow news.

Not even a year ago, resorts’ hopes hinged on snow during televised Broncos games. Resorts issued snowfall totals a day after the snow fell. They bought powdery ads in magazines six months before the season began.

The idea was that resort reservation desks were inundated with calls when football stadiums were frosted white, and last year’s photos of untrammeled snow were good enough.

But by 5 a.m. this frosty Christmas week morning, the news of new snow was posted on websites for Vail, Beaver Creek, Breckenridge and Keystone, the four resorts that host more than a third of Colorado’s roughly 12 million annual skier visits. It was waiting in the inboxes of thousands of skiers. Newspapers, radio and TV stations had it ready for morning reports.

Copper Mountain and Sunlight have eliminated the middlemen like Semrow — allowing Web surfers to check the snow themselves via webcam.

“Now we see that blip (of vacation interest and bookings) as soon as the first flake flies,” Jarnot said.

Vail Resorts held back about 80 percent of its multimillion-dollar winter marketing campaign by skipping the traditional one-page ads in national magazines like Outside, Men’s Health and Conde Nast Traveler. Instead, the company joined the social-networking revolution and now e-pitches its powder.

The company took the money it would have spent on those pricey magazine ads and kept it for up-to-date campaigns issued through e-mail, newspapers, search-engine display ads and online banners.

It’s a plan that works with skiers’ changing habits: Where they once booked holidays months in advance, today they are increasingly apt to book the week before.

“We have the arsenal to make the blitz,” Vail Resorts chief executive Rob Katz told a forum of cable executives in Denver in October. “And ultimately, it’s a bit of a waiting game to guess when the customers are making their decision.”

One of the best tools for guessing when skiers will pull the trigger on a holiday is snowfall. Not that every ski vacationer loves powder, says the marketing team.

“We still get calls from people worried about too much powder,” said Vail ski area spokeswoman Liz Biebl.

Still, everyone loves at least enough snow to cover the rocks. Resorts like to open all their skiable terrain. Neither has happened yet this season in the state’s central Rockies, making the powder pitch something of a challenge.

Even the southern ski areas — where snowfall in the early season has been abundant — rely on snowy reports from the big resorts like Vail and Aspen.

“We have been open 100 percent since the beginning of the season, but it’s not until Vail and Telluride post double-digit dumps that people actually believe it’s as good as it is,” said Aaron Brill, owner of Silverton Mountain, where a 50-inch base ranks second-deepest in the state. “Vail’s snow message is almost as important to us as it is for them, unfortunately.”

Photographer Jack Affleck has worked for 20 years shooting skiers plundering powder for Vail Resorts. His team of a dozen “snow message” photographers and videographers springs into action at all four Vail Resorts hills whenever depths reach 6 or so inches. He loads the chairlift with his star skiers at 7:10 a.m. and has a few favorite locations to shoot athletes in hard-charging turns with powder flying overhead.

When he started in the late ’80s, Affleck would race down the hill, develop and scan his film, and the images would be in New York and Chicago by 3 p.m. to make news deadlines. Today, he snaps quick shots with his camera phone and posts to Twitter as early as 7:15 a.m. Video and high-quality shots are transmitted an hour later, arriving on skier phones before the lifts start turning.

By midmorning, the world is awash in Colorado’s powder.

Or that’s the idea.

“That hasn’t happened too much this season,” Affleck said. “We have this game plan like a military operation, and it just hasn’t come.”

Jason Blevins: 303-954-1374 or jblevins@denverpost.com