Thunderstorm Outlook
Issued at 8:07am 2/09/2026
Valid from 8:07am 2/09/2026 to Midnight 2/09/2026
A showery northwest flow spreads onto the western areas of the South Island during today. There is a low risk of thunderstorms for Fiordland and Stewart Island from late morning until late afternoon and for the Westland District during the afternoon and early evening. There is minimal risk of thunderstorms or significant convection elsewhere during this period.
Issued at 7:26pm 2/09/2026
Valid from Midnight 2/09/2026 to Midday 3/09/2026
There is minimal risk of thunderstorms or significant convection during this period.
Issued at 8:50am 2/09/2026
Valid from Midday 3/09/2026 to Midnight 3/09/2026
A showery northwest flow spreads onto the western areas of the South Island during the second half of Thursday ahead of an active front which moves onto the lower South Island late in the day. There is a low risk of thunderstorms for the Westland District and Fiordland from late evening, but a moderate risk for northern Fiordland and southern Westland at night. If thunderstorms do occur they could boost rainfall intensities to 10 to 25 mm/h. There is minimal risk of thunderstorms or significant convection elsewhere 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.
