Severe Weather Outlook

Issued: 10:34am Saturday 22 Feb 2025

Valid Monday 24-Feb-2025

A large high covers most of the country. A front over the Tasman Sea is expected to reach the south of the South Island at night.

There is minimal risk of severe weather affecting the country.

Valid Tuesday 25-Feb-2025

A ridge of high pressure continues to lie over the North Island, while a cold front and associated rain-band move northwards over the South Island. A period of heavy rain is likely about Fiordland and the Westland ranges with the front and there is low confidence that accumulations over Fiordland will be enough to warrant a warning.

Valid Wednesday 26-Feb-2025

The front weakens and becomes slow-moving over the southern North Island while a ridge of high pressure spreads over the South Island.

There is minimal risk of severe weather affecting the country.

Valid Thursday 27-Feb-2025

The ridge of high pressure expands to cover most of the country and there is minimal risk of severe weather.

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 Sunday, 23-Feb-2025

Issued: 6:35am Sunday 23 Feb 2025

No thunderstorms or significant convection expected 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.