When the Today show’s Al Roker attempts to set a new record for continuous weathercasting, he’ll be looking to neither Jerry Lewis nor Strom Thurmond as inspiration for sheer iron-assed endurance.

“I would go with Tom Brokaw,” the hambone meteorologist tells me, mentioning a possible exemplar for the “Rokerthon,” an event that even NBC admits is a stunt (though it will also serve as a fundraising vehicle for Roker’s favorite charity, the USO). It commences Wednesday night at 10 p.m. on MSNBC’s The Last Word with Lawrence O’Donnell, will be live-streamed online and carried on more than 220 NBC affiliates nationwide, plus stations in Canada and Australia, show up on CNBC and the NBC Nightly News, and, if all goes well, will end 34 hours after it began at 8 a.m. Friday on Today.

“Tom Brokaw would anchor for hours on end for breaking news events and things like that,” Roker says. “Just kind of a measured sort of cadence and presence.”

The often over-the-top Roker, Today’s resident cutup, could seldom be described as measured. It’s unlikely that he’ll be impersonating the network’s longtime alpha anchorman, or for that matter the Muscular Dystrophy Telethon king or the late South Carolina Dixiecrat, who notoriously filibustered the 1957 Civil Rights Act for 24 hours and 18 minutes, placing a bucket in the cloakroom, just off the Senate floor, to prevent an embarrassing accident. (Not that Thurmond’s misguided exertions weren’t embarrassing in themselves.)

Roker’s true role model—indeed, rival—is Norwegian meteorologist Eli Kari Gjengedal, who in September spent slightly longer than 33 continuous hours presenting the weather on Norway’s TV2, thus forecasting her way into The Guinness Book of World Records and breaking the previous milestone by just over nine hours.

“We had a story about this woman in Norway and her nonstop live broadcast,” Roker recounts, “and I kind of flippantly said, ‘I can do that. Sure, I’ll do that.’…And everybody said, ‘Wow. You’re gonna do that?’ And I said, ‘Yeah, I guess so. Why not? It could be fun. It’s a challenge.’”

Enter ABC News correspondent Deborah Roberts, the 60-year-old Roker’s spouse since 1995. “She was concerned about this and made sure I got checked out,” says Roker, who famously underwent gastric bypass surgery a decade ago after topping 340 pounds, dropping to 190 at one point, and has since gone under the knife for various orthopedic procedures. “But I’ve gotten a clean bill of health from the NBC medical doctors…Look, if I get to the point where I’m not feeling well, I’ll be the first to pull the plug. Because I’m not gonna kill myself or risk any kind of health issues just to do this.”

Roker says he has been steeling himself to acquire “that kind of attitude that you’ve got to have—that you’re in it for the long haul, and you’re there to have a good time. I will be on camera constantly, but the Guinness rules allow that for every hour you’re on, you get five minutes off. So if you go two hours, you get 10 minutes. And when you think about it, look, when you go to the movies, you sit through an over-two-hour movie, you don’t go to the bathroom. When you’re of a certain age, as I am, you sleep for at least a few hours before you are awakened by nature’s call.”

Roker insists that he’ll be able to stay alert during the marathon, though he can’t say quite how. “I don’t know,” he says. “I just know I will.”

It’s “No-Shave November,” the American Cancer Society’s and the Today show’s bid to boost public awareness of men’s health concerns, so Roker won’t be using a razor—or worrying about how ragged he’ll look after, say, 24 hours on camera. “I don’t look that great to begin with,” he claims with undue modesty. “I don’t really think there’s going to be that noticeable a difference.”

He adds, “I’ll probably change shirts and undergarments and things like that. Maybe change a jacket. Just kinda, you know, freshen up.”

Broadcasting from the Today green room, with a window that looks out on Rockefeller Plaza, Roker says he’ll be supported by three round-the-clock teams of two meteorologists each, and sticking mostly to the weather, though occasionally engaging in five or 10 minutes of banter here and here. “But you’ve gotta be talking about weather. We’re doing international weather, Canadian weather, weather broken down by region. So there’s more than enough stuff to talk about…People can come by and ask for forecasts. We got social media. I’ll be tweeting with people. Hashtag Rokerthon. It’s 360, baby!”

While Roker expects several of his Today colleagues to join him during the night (and perhaps keep him from dozing off), Deborah Roberts will probably be a no-show, he says. “My wife will not show up, but she will be there in spirit…I think if she has trouble sleeping, she might swing by the window and blow me a couple of kisses.”

Roker rejects the idea that he’ll be the weather equivalent of David Blaine—the magician who places himself in ridiculously stressful situations for the entertainment of a prurient public. “First of all, David Blaine is an extremely skilled performer and very attractive. I am neither,” Roker insists. “I have basically built my career on ‘average.’ And any time I can get above that—wow, that’s a home run. I keep the bar at a medium level.”

Nor is the Rokerthon, he says, a gimmick to lure viewers to Today, which lost its first-place dominance to ABC’s Good Morning America in 2012 after much of the audience blamed cohost Ann Curry’s abrupt departure on Matt Lauer. (In the wake of Curry’s painful leave-taking, after Lauer told members of the women’s Olympic rowing team about a New York post-race tradition of “throwing her [a teammate] in the Hudson River,” Roker joked pointedly on the air, “Which is different than our tradition—which is you throw one of us under the bus, but that’s another story.”)

“I don’t know if it’s gonna lure viewers,” Roker says. “I think it’s just kind of a fun thing to do if people tune in. Because the fact of the matter is the Today show part is really, in a way, the smallest part in the great 34-hour scheme of it. It’s more about trying to raise money and doing something that hasn’t been done before.”