Weather will play a big part in the success of Labor Day weekend for many Forsyth businesses. With Hurricane Isaac moving into the U.S. interior, and likely bringing continued rainfall to the metro Atlanta area, Lake Lanier businesses are hoping for a decent holiday stretch.“The percentage [for chance of rain] is down to about 30 or so, but what worries me is some people see that and they’re like, ‘Oh, let’s not chance it,’ especially on a boat rental,” said William Archer, vice president of boat rentals with Port Royale on Lake Lanier in northeastern Forsyth County. Archer called the weekend “the last big hoorah” of the summer for his and other lake businesses.