'Large, damaging hail': Severe thunderstorm warning issued for Canterbury

A Canterbury farmer has captured footage of a tornado as severe weather rolled through the region on Thursday evening.Tommy Glanville was on his farm near Rakaia when the storm hit.MetService said a "small transient tornado" hit parts of Canterbury.Earlier MetService warned large and damaging hail could hit parts of Canterbury as severe thunderstorms swept up part of the South Island.MetService has a severe thunderstorm watch in force for Christchurch and the Canterbury Plains until 8pm."They could be severe and accompanied by large, damaging hail, larger than 20mm diameter," MetService said."Large hail can cause significant damage to crops, orchards, vines, glasshouses and vehicles, and make driving conditions hazardous."Hail in the Canterbury town of Leeston.Supplied / Charlie BarracloughThe National Emergency Management Agency advised people to take shelter indoors away from windows, avoid sheltering under trees, get back on land if anyone was on the water, move cars under cover or away from trees, secure any loose items around their home, check their gutters and drains were clear, and be ready to slow down or stop if they were driving.Hail in the Canterbury town of Leeston.Supplied / Charlie BarracloughDuring and after the storm, the agency said people should beware of fallen power lines and trees, and avoid streams and drains in case there was flash flooding.