Outdoor plans for many will be in jeopardy through the weekend as rain gathers in the Appalachians and slowly advances across the mid-Atlantic and New England, AccuWeather meteorologists say. Meanwhile, cool air will invade from the opposite direction and add to the damp conditions. For many, May weekends are an opportunity to spend more time outdoors. However, in keeping in step with many weekends since the winter, wet weather has returned to the Northeast. A front with cool air pushed westward