Issued at 7:52am 23/01/2026
Valid from 7:52am 23/01/2026 to 1:00am 24/01/2026
An unstable west to southwest flow spreads across southern and central New Zealand today. A broad moderate risk of thunderstorms spreads northwards from northern parts of Central Otago and Canterbury later this morning to Marlborough and Nelson Lakes this afternoon and evening, with localised heavy rain and hail. In addition, there is a moderate risk of SEVERE THUNDERSTORMS this afternoon and evening over inland and northern Canterbury, with localised downpours of 25 to 40 mm/h and large hail in excess of 2 cm in diameter. A low risk of thunderstorms also extends over southern parts of Central Otago and the Queenstown Lakes District, North Otago and northern Westland. A couple of troughs move across the northwest of the South Island today, with a moderate risk of thunderstorms for Grey, Buller and parts of Tasman this afternoon and again tonight. These thunderstorms may produce brief heavy rain and hail, and a slight chance of a small coastal tornado. A broad low risk of thunderstorms then spreads to the southwest of the North Island from Waitomo to Kapiti later this afternoon. No thunderstorms or severe convection expected over the remainder of New Zealand.

Issued at 8:53am 23/01/2026
Valid from 1:00am 24/01/2026 to 1:00pm 24/01/2026
Unstable west to southwest conditions spread across central and northern parts of New Zealand through the period, with a broad low risk of thunderstorms from the far north of Canterbury and Buller before dawn, spreading to Auckland and Bay of Plenty later in the morning. The risk of thunderstorms is considered moderate however from Waikato to the Kaikoura Coast as depicted on the chart, with heavy rain and small hail, and strong wind gusts of 90 km/h. Note, there is also a low risk of localised downpours on a southerly change from the Kaikoura Coast to Wellington and southern Wairarapa in the early morning. No thunderstorms or severe convection expected over the remainder of New Zealand.

In New Zealand, MetService classifies a thunderstorm as severe if one or more of the following criteria are met:
Rainfall of 25mm/h, or more.
Hailstones 20mm in diameter, or larger.
Gusts of 110km/h (60 knots) or stronger.
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.