Thunderstorm Outlook
Issued at 7:23am 10/09/2026
Valid from 7:23am 10/09/2026 to Midnight 10/09/2026
A front moves northeast over the North Island this afternoon and evening bringing a period of rain or frequent showers, especially in the west. There are some areas with a low risk of thunderstorms associated with the front. There is a low risk of thunderstorms during the afternoon for the north and west of Taranaki, during the afternoon and evening for Waitomo and Waikato, and in the evening and at night for Auckland and Northland. These thunderstorms may be accompanied by heavy rain, with intensities of 10 to 15 mm/h. There is minimal risk of thunderstorms or significant convection elsewhere during this period.
Issued at 8:58am 10/09/2026
Valid from Midnight 10/09/2026 to Midday 11/09/2026
There is minimal risk of thunderstorms or significant convection during this period.
Issued at 9:09am 10/09/2026
Valid from Midday 11/09/2026 to Midnight 11/09/2026
A weak front moves quickly northeast over the southeast of the South Island bringing a period of frequent showers in the afternoon. There is a low risk of thunderstorms about coastal Clutha in the afternoon. There is minimal risk of thunderstorms or significant convection elsewhere 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.
