The low-lying roll cloud spanned across the horizon at the shoreline of Rhode Island with viewers claiming the ominous sight looked like the apocalypse<br />Chilling video has emerged of what appeared to be an apocalyptic vision as a thick rolling cloud sweeps across the seafront in the US.<br /><br />In a video taken by Jim C on a ferry, the impressive cloud spans hundreds of miles along the Old Harbor on Block Island off the coast of Rhode Island.<br /><br />Block Island Tourism said the phenomenon appeared last Saturday. It may simply have been just a rare weather phenomenon, but the chilling sight led many viewers to reach their own sensational conclusions.<br /><br />Some related the weather phenomenon to some "doomsday" vision sent by God.<br /><br />One said: "Perhaps a sign before Passover that God has sent a plague to convey his dissatisfaction with certain things."<br />Another one quoted a verse from the Bible and wrote: "Luke 21:11 Verse Concepts and there will be great earthquakes, and in various places plagues and famines; and there will be terrors and great signs from heaven."<br /><br />Others likened the sight to a scene from apocalyptic blockbuster the Day After Tomorrow.<br /><br />The weather phenomenon is known as a roll cloud. Explaining the sight, one viewer said: "That happens when a cold front passes – not unusual – it snowed this morning and by midday, was beautiful outdoors."<br /><br />Bonnie Diamond, press officer at the Met Office told Daily Star Online: "The cloud in this picture looks like an Arcus cloud, of which there are two types – shelf cloud and roll cloud.<br /><br />"These are long, thin, low-level clouds typically associated with unstable air and thunderstorms."<br />It forms when a cold downdraft from a cumulonimbus cloud reaches the ground and the cold air spread rapidly along the ground, pushing existing warm moist air upwards.<br />And as this air rises, water vapour condenses into the patterns associated with Arcus clouds.<br /><br />
