Thunderstorm Outlook
Issued at 8:37am 22/04/2026
Valid from 8:37am 22/04/2026 to Midnight 22/04/2026
A showery southerly flow persists about the eastern areas of central New Zealand today and there is a low risk of thunderstorms for coastal Wairarapa, southern Wellington and the Cook Strait from tonight as depicted on the chart, which brings a period of heavy showers with possible small hail. There is minimal risk of thunderstorms or significant convection elsewhere.
Issued at 9:30am 22/04/2026
Valid from Midnight 22/04/2026 to Midday 23/04/2026
A showery southerly flow persists about central New Zealand during Thursday morning and there is a low risk of thunderstorms for coastal Wairarapa, southern Wellington, the Cook Strait and South Taranaki before dawn as depicted on the chart, which brings a period of heavy showers with possible small hail. There is minimal risk of thunderstorms or significant convection elsewhere.
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.
