Severe Weather Outlook

Issued: 10:32am Saturday 31 May 2025

Valid Monday 02-Jun-2025

A large high over the Tasman Sea extends a ridge onto the North Island, and a northwest flow develops over the South Island.

There is minimal risk of severe weather.

Valid Tuesday 03-Jun-2025

The ridge of high pressure over the North Island starts to weaken, and a northwest flow affects central and southern New Zealand.

A front is expected to bring rain to Fiordland, and there is low confidence of warning amounts of rain there.

Valid Wednesday 04-Jun-2025

A low pressure system moves onto central and southern New Zealand, while an associated front moves onto the North Island.

There is low confidence for warning amounts of rain in Northland, eastern Bay of Plenty, northern Tasman/Nelson and the northwest of Marlborough, Buller, and the ranges of Grey and northern Westland. There is also low confidence of warning amounts of rain in Fiordland in the morning.

There is also low confidence for severe northwest gales in areas of the North Island north of approximately Waitomo, Taihape and Central Hawke's Bay, and also about South Taranaki, Wellington, southern Wairarapa and the Marlborough sounds.

Valid Thursday 05-Jun-2025

The low pressure system and associated front should move away to the east of New Zealand early morning, and there is low confidence of warning amounts of rain in eastern Bay of Plenty at first.

A showery west to southwest flow then spreads across the country.

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, 01-Jun-2025

Issued: 7:51pm Saturday 31 May 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.