Severe Weather Outlook

Issued: 10:12am Sunday 1 Nov 2026

Valid Tuesday 03-Nov-2026

A slow-moving front over the central South Island is forecast to weaken.

There is moderate confidence heavy rain will continue to fall about the ranges of the Westland District from the glaciers northwards during the morning, with further spillover into the adjacent headwaters of the Canterbury lakes and rivers also possible.

Valid Wednesday 04-Nov-2026

A humid north to northwest flow covers New Zealand, with embedded weak fronts expected to bring rain to mainly northern and western regions.

There is low confidence rainfall amounts will reach warning criteria about the ranges of the Westland District from the glaciers northwards.

Valid Thursday 05-Nov-2026

A humid north to northwest flow covers New Zealand, with embedded weak fronts expected to bring periods of rain to mainly northern and western regions.

There is low confidence rainfall amounts will reach warning criteria about the ranges of the Westland District.

Valid Friday 06-Nov-2026

A humid north to northwest flow covers New Zealand, with embedded weak fronts expected to bring periods of rain to mainly northern and western regions, which may be heavy for a time. A trough, which brings a change to cooler southwesterly winds, is forecast to move over southern New Zealand.

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, 01-Nov-2026

Issued: 7:23am Sunday 1 Nov 2026

There is minimal risk of thunderstorms or significant convection during this period.



Valid to Noon Monday, 02-Nov-2026

Issued: 10:15am Sunday 1 Nov 2026

A front moves onto the southern South Island during the morning. As the front moves over northern Fiordland and southern Westland between dawn and midday there is a low risk of thunderstorms. Regardless of whether thunderstorms occur or not, heavy rain is expected with the front. Elsewhere, the risk of severe convection or thunderstorms is minimal.



Valid to Midnight Monday, 02-Nov-2026

Issued: 10:17am Sunday 1 Nov 2026

During the afternoon and evening a front moves over the southeast of the South Island. There is a low risk of thunderstorms during the afternoon and early evening about parts of Central Otago, Dunedin, North Otago and coastal South Canterbury. Elsewhere, the risk of severe convection or thunderstorms is minimal.



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.