Want to take a live tour of The Weather Channel, the 24-hour cable network that just got a $3.5 billion buyout offer from NBC Universal and two equity firms? Well, you can’t.

It’s not because the channel’s current owners, Landmark Communications, are inhospitable. In fact, they’ve conducted very popular live tours of the outlet’s Atlanta broadcast studios for years.

Not the ones in use, of course; weather analysts don’t usually work with live audiences Conan O’Brien-style. But The Weather Channel is seen in 97% of U.S. cable-equipped homes and has the third widest distribution in the medium. You don’t achieve that kind of reach without attracting some meteorological groupies who want to see where their faves keep an eye on those tropical depressions in the Gulf of Mexico.

No, what’s ruling out the live studio tours has been a tech upgrade. On June 2 the channel began broadcasting in high definition after spending $60 million on a new studio facility, including a high-def weather screen that’s the size of a tennis court.

Switching to HD will let viewers practically see individual snowflakes in the next blizzard report from Bemidji MN. (It was probably also a necessary decision for finding a buyer for the channel, something Landmark has been publicly doing since January.) But the sensitive new equipment for the HD feed has made public tours too risky. In fact, the high-gain audio gear would be able to pick up the sound of tour groups tromping anywhere near a broadcast and send it out live to viewers.

So to satisfy their avid fans while preserving stage silence, The Weather Channel turned to another kind of technology: its Web site, www.weather.com. The site gets heavy traffic; with some 40 million unique visitors a month, it’s the number one Web site for weather and the 14th most popular site of any kind. And that, the channel decided, made it the obvious place to locate a virtual studio tour.

Cisco Networking Solutions had worked with The Weather Channel to assemble the HD broadcast studio and was interested in sponsoring the virtual Web tour of the facilities. But they wanted the Web feature to be more interactive than the standard “movie-style” virtual tour, built with QuickTime.

So The Weather Channel turned to The SuperGroup, an Atlanta agency that created some innovative Web campaigns for the channel last winter. (“Weather Channel Grabs Some Viral Air”)

“Everyone has seen the QuickTime virtual reality tours,” says Chris Wallace, leader of the agency’s interactive division. “But that has traditionally required a very large download, and it’s usually just imagery with no real interaction. It also requires the QuickTime plug-in, which not everybody has.” That’s especially true of the older demographic that makes up the die-hard Weather Channel fan. That kind of complicated 1-D experience wasn’t what Cisco was hoping to be associated with.

Instead, The SuperGroup built a virtual tour site that auto-launches a video introduction from meteorologist Jim Cantore. The tour is built in PaperVision, a lightweight extension of the Flash programming language that gives Flash the 3-D perspective it doesn’t have in its basic form.

The tour divides the studio area into four main sections: the work desk, the anchor desk, the interview chair and the side room. Visitors can move their cursor around the room and click on the four areas. Each section then offers five interactive points visitors can click on to get more of the kind of inside information they would normally acquire in a live tour (for example, that HD lenses require a wider camera perspective, so the new studio is four stories tall) along with discreet mentions of the new Cisco equipment installed.

“It’s nothing that will take you hours to explore, but it’s definitely a richer online experience than your basic virtual tour of online real estate listings,” Wallace says.

Visitors can also check out a slide show of the new studio’s year-long construction process, videos of its “green” designs and clips of favorite Weather Channel meteorologists talking up the virtues of high-def broadcasting.

“The Weather Channel wanted to use the Web site to educate loyal viewers on, one, why HD is a big deal and, two, why they’re no longer allowing live tours,” Wallace says. “I think the content conveys that they’re really thrilled to be the first major newsgathering organization to broadcast in HD.”

To promote the switch to HD and the Web walkthrough, The Weather Channel ran a countdown clock for the month before the changeover, Web trivia questions about the studio and a sweepstakes promotion that awarded a trip for four to Atlanta to see the HD studio live.

Cisco has also made hay of the HD switch and the virtual tour by rolling out a microsite for mobile users that offers up the welcome video from Cantone, information about the tour and links to Cisco’s main mobile Web site.

For the foreseeable future the Web studio tour will retain the “HD experience enabled by Cisco” branding, but Wallace says the sponsorship is time-limited and that some other marketer may take over that role in the future.

The new Weather Channel online tour may hold almost as much sex appeal for armchair storm trackers as the new high-def broadcast capabilities do. And that’s a lot of appeal. As one meteorologist says in a quote on the Web site, the excitement of HD broadcasting will “make it seem like the tornado’s right there in your living room.”

The rest of us will probably continue to puzzle over why that’s a good thing.