Thunderstorm Outlook
Issued at 7:15am 11/06/2026
Valid from 7:15am 11/06/2026 to Midnight 11/06/2026
A cold front moves onto the southern South Island late today bringing rain to the area, with brief heavy falls about Fiordland and coastal Southland. There is an associated low risk of a few thunderstorms embedded within the rain-band about Stewart Island and Fiordland from this evening. There is a minimal risk of thunderstorms or severe convection over other parts of New Zealand today.
Issued at 7:38pm 11/06/2026
Valid from Midnight 11/06/2026 to Midday 12/06/2026
Chart reviewed at 7:35pm Thursday and no changes made. A cold front moves slowly northwards over the southern and central South Island on Friday morning with a band of rain. There is a low risk of a few thunderstorms embedded within the rain-band over northern Fiordland and the far south of Westland before dawn, with heavy rain. There is a minimal risk of thunderstorms of significant convection expected over other parts of New Zealand on Friday morning.
Issued at 8:08am 11/06/2026
Valid from Midday 12/06/2026 to Midnight 12/06/2026
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.
