Issued at 7:35am 16/04/2026

Valid from 7:35am 16/04/2026 to Midnight 16/04/2026

An unstable southwest flow covers much of the country. Within this flow, several fronts are expected to pass over New Zealand during the day. The main risk of thunderstorms is in the west and south of the South Island. There is a moderate risk of thunderstorms this morning and afternoon for western Tasman, Buller, coastal Grey and Westland, Fiordland, Southland and Clutha. If thunderstorms occur, they are likely to be accompanied by localised heavy rain with intensities of 10 to 15 mm per hour, small hail in the west and hail with diameters 5 to 15 mm in the south. In the south, strong wind gusts of 90 to 100 km/h are also possible. Although the risk eases in the afternoon it remains low. There is a low risk of thunderstorms throughout the day further inland for the west and south of the South Island as shown on the chart, and this afternoon and evening a low risk of thunderstorms spreads over the eastern parts of the South Island. About the North Island, there is a low risk of thunderstorms this morning from Waitomo to central Northland and across Bay of Plenty to inland Gisborne/Tairawhiti. For the rest of Northland, as well as Whanganui and southern Taranaki there is a low risk of thunderstorms this morning and afternoon. Not shown on the chart, there is also a moderate risk of thunderstorms about the Chatham Islands this morning and afternoon. Elsewhere, the risk of thunderstorms or severe convection is minimal.

Issued at 7:31pm 16/04/2026

Valid from Midnight 16/04/2026 to Midday 17/04/2026

A northwest flow over the country strengthens ahead of a front that should reach the southern South Island late morning. There is a low risk of thunderstorms about the Chatham Islands before dawn. During the morning, a high risk of thunderstorms spreads onto Fiordland and southern Westland. These thunderstorms may be accompanied by localised heavy rain with intensities of 15 to 25 mm per hour and strong wind gusts of 90 to 100 km/h. A low risk of thunderstorms extends further north and east from the moderate risk area as depicted on the chart. Elsewhere, the risk of severe convection or thunderstorms is minimal.

Issued at 10:22am 16/04/2026

Valid from Midday 17/04/2026 to Midnight 17/04/2026

During the afternoon and evening, fronts continue to move northwards over the South Island. There is a moderate risk of thunderstorms about the west and Southern Alps of the South Island, about Fiordland in the afternoon, Westland during the afternoon and evening and in Grey and Buller in the evening and at night. These thunderstorms may bring localised heavy rain with intensities of 15 to 25 mm per hour, or possibly more about the Westland ranges, and strong wind gusts of 90 to 100 km/h. A low risk of thunderstorms extends further north and east, covering western Tasman, inland areas of Canterbury and Otago, and western Southland. From evening, there is also a low risk of thunderstorms about coastal Waitomo, Taranaki, Horowhenua and Kapiti. Elsewhere, the risk of severe convection or thunderstorms is minimal.