MetService has issued a severe thunderstorm watch for the South Island

A series of fronts are moving around the country - with warm air up towards the North and colder air down South.

The yellow severe thunderstorm watch applies from 3pm this afternoon until 9pm tonight.

It includes Christchurch, Canterbury Plains, the High Country, North Otago, Central Otago, Southern Lakes, Dunedin, Clutha, Southland and Fiordland.

The storms could also produce hail larger than 20 millimetres and surface or flash flooding.