Thunderstorm Outlook
Issued at 7:37am 24/04/2025
Valid from 7:37am 24/04/2025 to Midnight 24/04/2025
A trough brings showers to Northland. There is an associated low risk of thunderstorms with bursts of heavy rain in the far north during the morning and afternoon, as indicated on the chart. No thunderstorms or significant convection expected elsewhere today.
Issued at 6:21pm 24/04/2025
Valid from Midnight 24/04/2025 to Midday 25/04/2025
No thunderstorms or significant convection expected during this period.
Issued at 10:20am 24/04/2025
Valid from Midday 25/04/2025 to Midnight 25/04/2025
A trough lying offshore moves southwards over the far north of Northland during the afternoon and evening. There is an associated low risk of thunderstorms with bursts of heavy rain. No thunderstorms or significant convection expected elsewhere during the second half of Friday.
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.
