Thunderstorm Outlook
Issued at 7:29am 24/08/2026
Valid from 7:29am 24/08/2026 to Midnight 24/08/2026
There is minimal risk of thunderstorms or significant convection during this period.
Issued at 8:20am 24/08/2026
Valid from Midnight 24/08/2026 to Midday 25/08/2026
A front is expected to move on to the lower South Island during the early morning, then become slow moving. There is a low risk of thunderstorms about Fiordland north of West Cape, including the ranges south of Jackson Head, before dawn. There is minimal risk of thunderstorms or significant convection elsewhere during this period.
Issued at 8:21am 24/08/2026
Valid from Midday 25/08/2026 to Midnight 25/08/2026
There is minimal risk of thunderstorms or significant convection 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 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.
