H2O: Just Add Water (2006)

S2E1 Stormy Weather

Following her parents' divorce, Cleo's father insists that she take on more responsibility for her sister Kim, starting with a concert outing. However, on the night of the event, Cleo, Rikki, and Emma accidentally catch sight of the full moon and rush off to Mako Island, with Lewis trying to keep up. Once at the island, the girls experience a magical transformation in the Moon Pool, amplified by a rare planetary alignment. Emma gains the ability to create snow and frost, Rikki can summon lightning, and Cleo discovers she can control both wind and water. Realizing the danger of their powers after nearly harming Lewis, they understand the importance of mastering their new abilities before anyone else gets hurt.