A slow-moving system means rain could force those planning outdoor activities in the central and southern U.S. this holiday weekend to come up with a Plan B on one or more days.

Supercell thunderstorms will fire up in the afternoon and evening over northern Texas and southern Oklahoma. Large hail, possibly the size of golf balls or bigger, is the main threat, but we can’t rule out damaging wind gusts and an isolated tornado. The Dallas-Fort Worth Metroplex could see hail from these storms, so it’s best to park your car in a garage this afternoon and evening.

Expect unpleasant weather late this week and pencil in extra time if you are traveling, including from Philadelphia to New York City, Hartford, Providence and Boston.

Many of us have treasured childhood memories of our first trip to a theme park. Our parents also probably remember battling the extreme heat and surprise rainstorms. So with the opening of a brand-new theme park in Florida, we thought we’d share our team’s tried and true ways to plan for a day of fun.

People in several Colorado neighborhoods recorded stunning video as tornadoes raced through communities like Elizabeth and Bennett on Sunday. Dozens of homes were damaged across Elbert, Adams and Arapahoe counties.