An unusual, apocalyptic-looking cloud formed over Aba Tibetan and Qiang Autonomous Prefecture in southwest China’s Sichuan Province on Monday. /Sichuan online Photo

According to Aba’s meteorological bureau, this is a hail cloud, formed by strong convection in a cloud group in a short period of time. /Sichuan online Photo

Pictures of the cloud have been widely shared online, with netizens saying it looked “explosive”. /Sichuan online Photo