A massive dust storm covered parts of Arizona, including its capital Phoenix, leaving thousands without power. The National Weather Service described the dust storm as a “haboob,” which occurs when thunderstorms kick up sand from the desert floor,

A massive dust storm has swept through parts of the US state of Arizona. The thick wall of dark dust in Pinal County was carried by thunderstorm winds - a phenomenon known as a haboob, according to the National Weather Service. The term haboob comes from Arabic and refers to a "strong wind" or "gale".