CHICAGO — With chilling winds howling in the background, tightrope walker Nik Wallenda declared Friday he’s ready to attempt two back-to-back skyscraper crossings, one of them blindfolded.

For Sunday’s televised walks, the 35-year-old daredevil promised to uphold the Flying Wallendas family tradition of working without a net or harness. City officials said they’ve decided a state law requiring safety nets for aerial acts higher than 20 feet wasn’t intended for “elite” performers like him.

“For generations, we have walked without nets,” Wallenda told reporters at the aptly named Vertigo Sky Lounge. “It is hard for others to comprehend. But I’m confident that the wire is a safe haven and a net for me.” He would crouch to the safety of the quarter-size-diameter cable, he said, and hold on if winds whip too hard.

The Discovery Channel will use a 10-second delay for the broadcast, allowing producers to cut away if something goes wrong. Millions of viewers around the world are expected to watch.

First, Wallenda will walk uphill at a 15-degree angle from the nearly 600-foot Marina City west tower, one of the twin corncob-shaped buildings, across the Chicago River to the top of the Leo Burnett Building. That walk is 454 feet from point to point, more than two city blocks.

Then he’ll walk between the two Marina City towers wearing a blindfold, a walk of 94 feet.

The city’s notorious winds attracted him, Wallenda said Friday as a brewing storm triggered a high wind warning from the National Weather Service. “I’m glad I’m not walking today,” he said with a smile.

If gusts of 50 mph or higher are forecast Sunday, the walks will be postponed. In lesser winds, he will walk, using his balancing pole to steady himself.

A rescue crew will be ready to help should wind force Wallenda to lower himself and cling to the steel wire.