Issued at 7:32am 9/11/2026
Valid from 7:32am 9/11/2026 to 1:00am 10/11/2026
A low risk of embedded thunderstorms spreads southwards across most of the north of the North Island today, as indicated on the chart. The risk of thunderstorms is moderate for Waitomo, Taumarunui, western Taupo, western Bay of Plenty, Waikato, Coromandel Peninsula, Auckland, Great Barrier Island and Northland. There is also a low risk of localised downpours in these regions but for Northland and Auckland the risk of localised downpours is MODERATE and Severe Thunderstorm Watches are now in force for these regions. Thunderstorms will enhance rainfall rates up to 25 mm per hour, and may produce small hail. Localised downpours will generate rainfall rates of 25 to 40 mm per hour. There is minimal risk of thunderstorms or significant convection elsewhere in New Zealand during Monday.

Issued at 10:41am 9/11/2026
Valid from 1:00am 10/11/2026 to 1:00pm 10/11/2026
A warm, moist and unstable air mass covers central and northern New Zealand, with a low risk of both thunderstorms and localised downpours extending across many areas of the North Island as indicated on the chart, also northwest Nelson. For Northland, the risk of both thunderstorms and localised downpours is moderate during the first half of Tuesday, especially before dawn. Thunderstorms will produce localised rainfall rates up to 25 mm per hour, while localised downpours will bring rainfall rates of 25 to 40 mm per hour. Broad-scale Severe Weather Watches for heavy rain and a risk of localised downpours are now in force for many northern regions of the North Island. See www.metservice.com/warnings/home for more information. There is minimal risk of thunderstorms or severe convection elsewhere during the first half of Tuesday.

Issued at 10:53am 9/11/2026
Valid from 1:00pm 10/11/2026 to 1:00am 11/11/2026
A low risk of thunderstorms and/or localised downpours covers much of the North Island, as indicated on the chart, also northwest Nelson. The risk for Northland, Auckland and Coromandel Peninsula is moderate, however. Thunderstorms will generate heavy rainfall up to 25 mm per hour, while localised downpours will bring rainfall rates of 25 to 40 mm per hour. There is also a low risk of thunderstorms during the afternoon and early evening for Buller, Grey, Westland, southern Fiordland and Southland. However, for Southland from around Invercargill westwards and southeastern Fiordland the risk is considered moderate. Thunderstorms will generate localised heavy rain of 10 to 20 mm per hour. There is minimal risk of thunderstorms or severe convection elsewhere during this period.

In New Zealand, MetService classifies a thunderstorm as severe if one or more of the following criteria are met:
Rainfall of 25mm/h, or more.
Hailstones 20mm in diameter, or larger.
Gusts of 110km/h (60 knots) or stronger.
Fujita F1 - i.e. wind speeds greater than 116km/h (63 knots) or stronger.
Note: some tornadic systems such as funnel clouds, waterspouts and small land-based tornadoes are possible with thunderstorms that may not be classified as severe.