Thunderstorm Outlook
Issued at 7:33am 7/05/2024
Valid from 7:33am 7/05/2024 to Midnight 7/05/2024
The trough drifts northwards across Great Barrier Island and the north and east of Northland today, bringing a few heavy showers and a low risk of thunderstorms as depicted on the chart. No other thunderstorms or significant convection expected over New Zealand during this period.
Issued at 7:03pm 7/05/2024
Valid from Midnight 7/05/2024 to Midday 8/05/2024
No thunderstorms or significant convection expected during this period.
Issued at 8:55am 7/05/2024
Valid from Midday 8/05/2024 to Midnight 8/05/2024
An unstable southwest flow affects the far southeast of the South Island during the afternoon and evening, with a low risk of a few thunderstorms about Stewart Island and coastal Clutha. No other thunderstorms or significant convection expected over New Zealand 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.
