This is the terrifying moment a cloud threatened to develop into a full blown TORNADO over a row of family homes. Brave snapper Pat Kavanagh took this shot of an explosive black storm from the roof of his house in Taber, Canada last month. Expecting the sunny weather to take a turn for the worse he watched intently as the billows started spinning into a furious funnel (漏斗形物). This pic was created by stitching together multiple photographs in a vertical panorama (全景照片). (Photo: PAT KAVANAGH / CATERS NEWS)