SONOMA, Calif. -- Monday evening brought the kind of cold, wet weather grape growers don't want to see in the middle of May when millions of acres of vines are developing fruit clusters.Grapes need warm weather to grow, and the current stretch of wet and chilly weather wasn't proving it for Napa County growers.But they are coming along a bit slow this year and that turns out to be a good thing, since they're all wet. The manager of the Sebastopol Wine Club said there's a lot of concern the rainy weather will hurt the grapes.