You guys have it wrong. You want opening day to
start off cloudly, cool, and rainy. This chases away the less dedicated. The perfect scenario is for it to warm up and dry up right about 10am, but still look like rain - then to have the sun come out by early afternoon after many people have already ditched plans for going to the park that day.
If it's 75 and sunny on the 27th, Carowinds is going to be a freaking madhouse with the opening of Intimidator. It was cloudy and in the 40s for BORG's opening, and that sucker had a 3 hour line before noon. True, this was due in part to it's usual capacity problems and one-train operation, but people were still willing to wait that long to try it. The line was well out of the queue and wrapping around behind the skytower.
Maybe having a large portion of these peeps stuck in pass processing for the morning will save us if the weather is nice