George Clooney might just be Hollywood’s favorite weatherman, and “Up in the Air ” his latest prediction of cultural precipitation: gloomy today, with a chance of emotional drizzle tomorrow, and clouds of despair possible for the foreseeable future.

Clooney plays Ryan Bingham, a “corporate downsizing specialist” who travels the Midwest, firing people from their jobs.

He’s unmarried and blissful in his hotel-to-hotel, airport-to-airport existence.

Bingham’s the exception to the “no man is an island” concept, an isolated, dispassionate chunk of granite protruding through the icy gray sea of humanity.

But something happens to Bingham as he nears his 10-mil lionth frequent flier mile. His sister’s marriage looms and he meets a lovely compatriot, a fellow high-mileage traveler named Alex (Vera Farmiga).

Suddenly Bingham’s peaceful, uncomplicated existence is on the verge of a shake-up. The film is the story of Bingham’s realization that life may be more than it seems. Or . . . maybe not.

Clooney plays Bingham with the same easy gait that made “Out of Sight” so watchable, that made “Michael Clayton” one of the best pictures of 2008. Just playing himself, the man’s Cary Grant-attractive, Jimmy Stewart-likable.

Watching Clooney sell you on the joys of solitude or sell himself on the notion of sudden, unexpected emotion is fascinating, rewarding in some hard-todescribe way.

Watching Clooney cloak himself in characters who too often find themselves at the precipice of a deep inner void is even more intriguing.

He’s like Willie Loman (“Death of a Salesman”) with a funny bone—but instead of success as the elusive brass ring, Bingham grasps at love and perhaps, like Loman, reaches for all the wrong reasons.

“Up in the Air” is bitingly funny here and there, but it’s funny in the way you might find a clown juggling plastic balls in the rain to be funny until you stop to wonder why.

It’s not a dark comedy, more like a bleak comedy, filled with the hollow laughter of a happy life suddenly glimpsed from another angle, another view and with the realization that sometimes life’s like a fast car on a lonely two-lane highway. There’s no place to turn, no reason to brake—it’s not a problem if you love the solitude of the road, the wind in your hair. But when you stop making the best of it, what then?

If Clooney and company are indeed barometers of cultural Americana, bring an umbrella. I suspect we’re in for some rain.