Thunderstorm Outlook
Issued at 7:47am 2/02/2026
Valid from 7:47am 2/02/2026 to 1:00am 3/02/2026
A very warm and humid northwesterly flow covers the North Island during Monday, with scattered showers. As indicated on the chart, there is a low risk one or two of these showers may develop into thunderstorms from Waikato to Wairarapa during the afternoon and/or evening. No other thunderstorms or significant convection expected over New Zealand during this period.
Issued at 10:13am 2/02/2026
Valid from 1:00am 3/02/2026 to 1:00pm 3/02/2026
A low approaches the upper South Island from the Tasman Sea accompanied by colder air aloft, bringing more unstable conditions. During the morning, there is a low risk of thunderstorms from coastal Taranaki to Westland, including Marlborough. For Buller, however, the risk is moderate, and thunderstorms here could bring heavy rain of up to 20 mm/h, and possibly a small tornado. No thunderstorms or significant convection expected 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.
