Thunderstorm Outlook
Issued at 1:52pm 7/07/2026
Valid from 1:52pm 7/07/2026 to Midnight 7/07/2026
Updated 1.55pm to extend moderate risk into Bay of Plenty. No other changes. A broad and unstable flow covers the upper North Island, with a low passing over Northland. There is a broad low risk of thunderstorms from Waikato, Bay of Plenty and Gisborne northwards. In the east, there is a moderate risk of thunderstorms over northeast Northland this morning and afternoon, continuing through the afternoon and evening over southeast Northland, northern Auckland, Great Barrier Island, Coromandel Peninsula and Bay of Plenty. For the Far North and western parts of Northland, there is a moderate risk of thunderstorms from early afternoon. These thunderstorms could be accompanied by heavy rain of 10-20 mm/h (but up to 25 mm/h possible in Coromandel Peninsula) and hail of 10-15 mm. Finally, there is a low risk of embedded thunderstorms in a rain band that extends through southern Wairarapa. There is a minimal risk of thunderstorms or significant convection over other parts of New Zealand.
Issued at 8:09pm 7/07/2026
Valid from Midnight 7/07/2026 to Midday 8/07/2026
A low just east of the upper North Island moves slowly eastwards, and an unstable south to southeast flow brings showers to parts of the north and east. Before dawn there is a low risk from Northland to western Bay of Plenty, but a moderate risk about the Hauraki Gulf and Great Barrier Island, Coromandel Peninsula and East Cape. Thunderstorms here could bring heavy rain of 10 to 20 mm/hr and small hail. A low risk of thunderstorms continues through this period about coastal areas of Gisborne/Tairawhiti, also Wairarapa as depicted on the chart. There is a minimal risk of thunderstorms or significant convection over other parts of New Zealand.
Issued at 9:49am 7/07/2026
Valid from Midday 8/07/2026 to Midnight 8/07/2026
During Wednesday afternoon, there is still a low risk of thunderstorms over coastal Gisborne and also eastern Wairarapa. There is a minimal risk of thunderstorms or significant convection over other parts of New Zealand.
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 25mm/h, or more.
Large hail:
Hailstones 20mm in diameter, or larger.
Strong wind gusts (from thunderstorms):
Gusts of 110km/h (60 knots) or stronger.
Damaging tornadoes:
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.
