A woman was left stunned when a giant cloud phenomenon suddenly appeared in the sky above her. Stephanie Weller, 26, captured what is known as a shelf cloud; a variety of Arcus clouds that are a low, horizon formation that appear somewhat flat. On July 12, Stephanie began to pack up her things on a Navarre, Florida, beach as she noticed the waves were picking up and the sky behind her was turning dark. Then, as she began filming, she noticed the rare phenomenon form above her, the clouds appearing to merge into a dark black shelf floating low in the sky. Stephanie, who said she rarely uses social media, decided to post the video publicly, and it soon received a number of positive responses.