HUDSON, WIS. - Gus the Weather Guy babbled numbers that, apparently, were important -- at least to a select few among the crowd gathered before dawn Saturday in the pre-flight briefing room, also known as the Chateau Ballroom of the Hudson House Hotel.

"Altimeter, 30-point-one-one. Winds stay 5 knots, 340 to 360. Overcast 4,000. Winds, 3,000; 350 at 8," and so on, before, finally: "It's long johns time."

Ah, English.

The data, less so than the winter dressing hint, was vital. Bottom line: Conditions would be just right for the three dozen or so hot-air balloon pilots, and their variously tentative tagalong charges, to lift off from the grounds of E.P. Rock Elementary School as part of the 24th annual Hudson Hot Air Affair weekend.

One of those pilots, Steve Jacobs, who owns Stillwater Balloon in Lakeland just over the St. Croix River from Hudson, was listening to Gus attentively, even though he had already been carefully tracking the weather numbers.

Safely lifting off a hot-air balloon demands a maddening balance of weather conditions: some wind, but not blowing more than 6 to 8 miles per hour; sunshine or at least high clouds, and no snow or rain. In Minnesota and Wisconsin, that's a tall order. It's why 75 percent of scheduled flights are canceled.

It's just one aspect of ballooning that seems a little, well, disconcerting. But Jacobs and his wife have 17 children, and it's clear that he does not addle easily. Even after more than 20 years of flying balloons, averaging about 100 flights a year, the magical freedom of being carried where the wind alone carries you to your destination remains fresh each time.

"I love flying," said Jacobs, who bought Stillwater Balloon four years ago. "Everything else I do is just work."

Now mobilized, the pilots are scrambling in the schoolyard. The sun peeks over the horizon, bringing with it the ideal calmer winds that will carry them all in the same direction: south along the St. Croix River.

Like other pilots, Jacobs, with help from his brother Joe and Scott Dammer, unload a wicker basket. This one can hold about a dozen people, all of whom will soon regard Jacobs, a stranger 20 minutes ago, as The Most Important Man in Their Lives. In the middle of the basket are four propane tanks hooked to the burners, which will soon spit out a menacing tongue of flame with a roaring whoosh that will keep the balloon inflated and aloft.

Next comes what looks like an oversized gym bag, weighing more than 400 pounds. The balloon is inside.

Balloons of every color are coming to life, first looking wrinkled and forlorn rolled out in the snow, then rising to majestic glory as air fills them in amazingly short order. The bag, or envelope as it is properly called, is light and deceptively strong, made of ripstop nylon, Jacobs said, like a parachute. At the bottom of the balloon, tougher material called Nomex resists heat from the burner's flame.

This 300,000-cubic-foot balloon is dubbed the Sun Drop. Jacobs and his crew are inside, securing ropes and checking rigging.

And then, the balloon is suddenly aloft, catching the wind as Jacobs expected.

Jacobs' business is much more brisk in summer and, while autumn is picturesque in the river valley, the weather can be more tricky. "Guys love popping the question up here," he said. "But as soon as she sees the balloon, she pretty much knows what's going on."

As the snow-covered expanse of the St. Croix quietly drifts by below, as a startled deer bounds away, it becomes obvious that nearly everything about flying in a balloon is like almost nothing about flying in a plane: the elements, the sense of true flight, the blissful silence.

"Every flight's a little different," Jacobs said. "You land somewhere different every single time."

Despite being at the mercy of the wind, Jacobs deftly set the balloon near a roadside. He and his crew members, who had been following on the back roads, then deflated the balloon and trundled it back into the big gym bag.

Jim Anderson • 651-925-5039 • Twitter: @StribJAnderson