Severe Thunderstorms could cause a couple of issues in coastal and slightly inland parts of Canterbury

Valid from midnight Thu, 19 Feb to noon Fri, 20 Feb

A trough and active front move northwards over the South Island during Friday morning, bringing rain and/or showers to many areas.

There is broadly a low risk of thunderstorms through central and southern parts, as indicated on the chart, and showers in these areas may generate small hail. However, before dawn the risk is considered moderate for southern Westland, Fiordland and Stewart Island. These thunderstorms will enhance local rainfall rates (up to 25 mm per hour) and bring hail up to 10 mm diameter.

In the east, there is a moderate risk of thunderstorms for the Canterbury Plains from late morning onwards. Thunderstorms here will generate localised heavy rain up to 20 mm per hour, small hail and strong wind gusts up to 100 km/h.

There is minimal risk of thunderstorms or significant convection elsewhere during the first half of Friday.

Valid from noon Fri, 20 Feb to midnight Fri, 20 Feb

A low risk of thunderstorms embedded in showers persists through southern and eastern parts of the South Island during the afternoon, as indicated on the chart. Showers may bring small hail.

However, for the Canterbury Plains the risk is moderate during the afternoon. Thunderstorms here will generate localised heavy rain up to 20 mm per hour, small hail and strong wind gusts (up to 100 km/h).

There is minimal risk of thunderstorms or significant convection elsewhere during the second half of Friday.

Source Metservice