Thunderstorm Outlook
Issued at 7:43am 16/11/2025
Valid from 7:43am 16/11/2025 to 1:00am 17/11/2025
A ridge of high pressure covers most of New Zealand today, with a northeasterly flow developing over Northland. A few showers are expected to develop over Northland today, and there is a low risk of one or two developing into brief thunderstorms about northern and western parts of the region as indicated on the chart. No other thunderstorms or significant convection expected over New Zealand today.
Issued at 8:16am 16/11/2025
Valid from 1:00am 17/11/2025 to 1:00pm 17/11/2025
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.
