The South Island is in store for thunderstorms, lighting and heavy rain

MetService has issued a severe thunderstorm warning for Westland, Selwyn, Ashburton, Timaru and Mackenzie districts.

These thunderstorms are expected to be accompanied by torrential rain and damaging wind gusts.

MetService has also placed a orange heavy rain warning over Dunedin, Clutha and Southland, heaviest between 10pm and 11am tomorrow.

Mayor Jules Radich says people should make provisions while it's daylight - before the rain becomes a reality.