Strong gusts and intermittent rain swirled over Manhattan early Thursday but Big Bird and Snoopy stayed on track — albeit a slightly lower one — to please fans in the Macy's Thanksgiving Day Parade.

Officials waited until right before the 9 a.m. start to decide whether it was safe for the event's famous balloons to float through Midtown despite the wet and wind. The balloons will be kept closer to the ground than usual.

City officials said they based the decision on information from the National Weather Service, wind-measuring instruments along the route, and their own judgment.

"You don't want to ground the balloons and all of a sudden have the wind die," said Jarrod Bernstein, a spokesman for the New York City Office of Emergency Management.

The hot-air balloons have been grounded just once in the parade's 80-year history, in 1973.

Wind gusts could reach 35 mph Thursday, and rain and temperatures in the 40s were forecast. City guidelines call for grounding the parade's trademark balloons, such as Snoopy and Garfield, if winds reach 23 mph and gusts exceed 34 mph.

Those rules were put in place after 45 mph winds sent a Cat in the Hat balloon careening into a metal pole during the 1997 parade, leaving a woman in a coma.

During last year's event, two sisters, ages 11 and 26, were hurt by debris when a giant M&M's balloon snagged a streetlight. A city report said the mishap was not caused by the weather, but rather discrepancies between parade guidelines and actual conditions along the route.

Some balloons can be tethered to vehicles and essentially act as floats. This year's parade also had a handful of "balloonicles" — balloons powered by motorized vehicles — that are less susceptible to wind because they are grounded.

To protect against accidents, seven wind-measuring devices have been installed along the parade route, Bernstein said. Police officers assigned to each balloon will be able to communicate changing conditions to the handlers, who will in turn adjust the flight pattern.

The parade this year features 33 floats with themes as varied as Charlotte's Web and Barbie, almost a dozen marching bands from across the country, and celebrities including singers Barry Manilow, Gloria Estefan and Ciara.

Encased in parkas and hoods, the four members of the Castellanos family were on the hunt for a good spot near Herald Square. They had traveled from Baltimore just for the parade and weren't going to be put off by the weather.

"We knew it was going to be bad," mom Lisa Castellanos, 35, said as the parade began. "But we're here already."

John Piper, who directs the Macy's studio that makes the balloons and floats, said he was most excited for people to see a new balloon inspired by the classic novel "Around the World in 80 Days."

"I think it's going to be just amazing," said Piper, who has been a part of the parade for 26 years.