Thunderstorm Outlook
Issued at 7:36am 3/07/2026
Valid from 7:36am 3/07/2026 to Midnight 3/07/2026
A front in the Tasman Sea approaches the southern South Island late this evening with rain spreading into Westland and Fiordland during the day. There is a low risk of a few thunderstorms embedded within the rain-band over Central and Southern Fiordland at night. There is a minimal risk of thunderstorms or significant convection over other parts of New Zealand on Friday.
Issued at 8:07pm 3/07/2026
Valid from Midnight 3/07/2026 to Midday 4/07/2026
A front is expected to move east over the lower South Island to reach southern Westland late Saturday morning. A second front follows over southern and central Fiordland late morning, heralding a showery westerly flow. There is a moderate risk of thunderstorms about Fiordland with the fronts, bringing localised heavy rain of 20 to 30 mm per hour, and possibly small hail with the second front. A low risk of thunderstorms extends to Stewart Island and north to central Westland. There is a minimal risk of thunderstorms or significant convection over remaining parts of New Zealand
Issued at 10:16am 3/07/2026
Valid from Midday 4/07/2026 to Midnight 4/07/2026
The main front progresses east during the second half of the day reaching Nelson at night, with the second front following over Fiordland and Westland bringing periods of more active showers. There is a moderate risk of thunderstorms about Fiordland during the period, which spreads into Westland during the evening and night, bringing localised heavy rainfall of 10 to 15mm, possibly 20mm per hour and 5 to 15mm hail. In addition, there is a low risk of thunderstorms about Stewart Island and coastal Southland during the period, which extends to Buller, western Tasman, northern Taranaki and the far north of Northland during the evening and night as indicated on the chart. 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.
