United States

Nik Wallenda points to Niagara Falls after a news conference in Niagara Falls, N.Y., Wednesday, May 2, 2012. Wallenda will try to cross the Niagara Gorge on a tightrope on June 15. The seventh-generation member of the Flying Wallendas spent months getting the necessary permissions from Canada and the United States for the cross-border stunt. (AP Photo/David Duprey)

Thousands of tourists have flocked to Niagara Falls to see Nik Wallenda, a seventh generation tightrope walker, walk 190 feet above Niagara Falls on a 2-inch-wide cable Friday night.

If the 1,771-foot-long walk can be completed, Wallenda will become the first person ever to walk across the falls in such close proximity.

Against his wishes, ABC will require Wallenda to be attached to a harness for safety reasons, yet the weather is still a concern as to whether he will be able to complete his walk across the falls.

In 1978, high winds in Puerto Rico caused unfavorable conditions for Nik's great-grandfather Karl, who took his last walk that day.

Though the wind was not the direct cause for Karl's fall, wind is a critical factor for the Wallendas when walking across a tightrope.

Wind was not an issue for Nick on June 18, 2011, who did the same walk that his great-grandfather did 33 years before, kneeling in the spot where he had fallen.

Friday night, however, weather should be of minor concern to Daredevil Wallenda.

When the walk begins Friday evening, sky conditions will be mainly clear, with the temperature in the mid-70s.

The winds will be calm, 4-8 mph at the surface; however, winds 190 feet above the ground, where Nik will be walking, will most likely reach 10-15 mph.

With the rope in such close proximity to the falls, mist will cover the tightrope, making it slippery, but Nik has prepared for some worst-case scenarios, simulating winds of over 55 mph and heavy mist on the rope in practice this week.

Wallenda expects he will reach the Canadian side of the falls from the New York side in only 40 minutes, with the weather conditions changing minimally over the course of his walk.

"It's been a dream of mine since I was six years old. Twenty-seven years I've been waiting and to do this, and it finally is coming true," said Wallenda in a May 2, 2012, press conference.

Wallenda is now 33 years old.

Nik's walk across the beautiful falls will viewed by millions of people across the world. Coverage of the event begins on ABC Friday at 8 p.m. Eastern time.

By Jessica Taheri, Meteorologist