An arcus cloud glided over Portland, Maine, amid a severe thunderstorm warning on September 15.
Dini Lamot was crossing Casco Bay on a ferry when he shot this footage of the shelf cloud. Lightning can be seen flashing in the distance.
The National Weather Service (NWS) issued a severe thunderstorm warning on Wednesday and shared a photo of a shelf cloud taken from nearby Casco on the same day. Credit: Dini Lamot via Storyful