Thunderstorm Outlook
Issued at 8:31am 4/11/2026
Valid from 8:31am 4/11/2026 to 1:00am 5/11/2026
A warm trough moves over eastern Northland during Wednesday morning and early afternoon, and brings a low risk of thunderstorms as indicated on the chart. Unstable conditions affect many parts of the country during the second half of Wednesday. There is a moderate risk of thunderstorms about Taihape and southern Taumarunui this afternoon and early evening, with localised heavy rain of 10-25mm/h. A surrounding low risk area extends from southern Waikato to southern Gisborne/Tairawhiti and Manawatu, as indicated on the chart. There is also a low risk of thunderstorms about western Northland during the afternoon, as well as Canterbury, eastern Otago, and Southland during the afternoon and early evening. There is a minimal risk of thunderstorms or significant convection elsewhere during Wednesday.
Issued at 9:14am 4/11/2026
Valid from 1:00am 5/11/2026 to 1:00pm 5/11/2026
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.
