Severe Weather Outlook

Issued: 10:48am Friday 24 Apr 2026

Valid Sunday 26-Apr-2026

A frontal rain band lies offshore northern Northland. In the far south of the country, a front could become slow moving for a time.

There is low confidence rain accumulations may approach the lower warning thresholds in Southland and Clutha. Additionally there is low confidence west to southwest winds may reach severe gale in exposed coastal places of Southland, Stewart Island and Clutha during the first part of the day.

Valid Monday 27-Apr-2026

A weak ridge of high pressure lies across central New Zealand, with weak southerly winds to its north and strong westerlies to its south.

There is minimal risk of severe weather affecting New Zealand.

Valid Tuesday 28-Apr-2026

A ridge of high pressure lies across New Zealand.

There is minimal risk of severe weather affecting the country.

Valid Wednesday 29-Apr-2026

A westerly flow covers the country, but a trough and associated fronts are expected to move onto the South Island.

There is low confidence for warning amount of rain in Fiordland.

Additionally, there is low confidence northwest northwest winds could become severe gale in exposed parts of Southland, Clutha and Otago, and turn severe southwest gale about coastal parts of Southland, Stewart Island, Clutha and Dunedin later.

Low confidence:

A 20% likelihood (or 1 chance in 5) of a warning being issued.

Moderate confidence:

A 40% likelihood (or 2 chances in 5) of a warning being issued.

High confidence:

a 60% likelihood (or 3 chances in 5) of a warning being issued.

New issues of this forecast are made available on this site at or before 16:30 NZST

Thunderstorm Outlook

Valid to Midnight Saturday, 25-Apr-2026

Issued: 8:07pm Friday 24 Apr 2026

The active trough is expected to move away to the north during Saturday afternoon. There is a low risk of thunderstorms about and north of Bay of Islands early afternoon, and also a low risk of localised downpours. No thunderstorms or significant convection expected elsewhere during this period.



Severe Thunderstorm Criteria

In New Zealand, MetService classifies a thunderstorm as severe if one or more of the following criteria are met:

Heavy rain (from thunderstorms):

Rainfall of 25 millimetres per hour, or more.

Large hail:

Hailstones 20 millimetres in diameter, or larger.

Strong wind gusts (from thunderstorms):

Gusts of 110 kilometres per hour / 60 knots or stronger.

Damaging tornadoes:

Fujita F1 (wind speeds greater than 116 kilometres per hour / 63 knots) or stronger.