Issued at 5:26pm 29/10/2026

Valid from 5:26pm 29/10/2026 to 1:00am 30/10/2026

Updated at 5:26pm to add a risk of severe thunderstorms for all of Christchurch City, the Banks Peninsula and coastal areas just south of it. Thunderstorms are likely this afternoon and into this evening. They could be Severe and accompanied by large damaging hail, larger than 20mm diameter. A Severe thunderstorm watch is in force. A front moves across the upper South Island this morning, bringing rain and increased instability. The front is followed by a cold unstable showery air mass. This morning there is a low risk of thunderstorms over the upper South Island from Buller to Marlborough Sounds, and any thunderstorms may be accompanied by heavy rain and strong winds, and this low risk spreads over the lower and central North Island this afternoon and evening as the front moves northeastwards. As cold air aloft spreads over southern and central New Zealand this morning, afternoon and evening, there is a general low risk of thunderstorms over both western and eastern parts of the South Island. From about Banks Peninsula to Wairarapa, however, the risk is moderate, and any thunderstorms here will likely bring heavy rain of up to 15 mm/h and small hail. There is minimal risk of thunderstorms or significant convection elsewhere during this period.

Issued at 8:05pm 29/10/2026

Valid from 1:00am 30/10/2026 to 1:00pm 30/10/2026

A cold and unstable west to southwest flow brings showers to southern and central New Zealand during Friday morning, and there is a general low risk of thunderstorms over southern and western parts of the South Island, as indicated on the chart. Late morning the low risk also affects Taranaki to Kapiti. A frontal wave moves over the upper South Island, and this is expected to bring heavier rain with a moderate risk of squally thunderstorms for Grey, Buller, the far west of Nelson and the Marlborough Sounds. Thunderstorms here are likely to be accompanied by heavy rain of up to 15 mm/hr, strong wind gusts of 90 to 100 km/h, small hail, and possibly small tornadoes. No thunderstorms or significant convection expected elsewhere during this period.

Issued at 11:11am 29/10/2026

Valid from 1:00pm 30/10/2026 to 1:00am 31/10/2026

Minor typo corrected at 11.10am During Friday afternoon and evening, cold air aloft over southern and central New Zealand gradually moves away to the east, and the frontal wave moves across the Chatham Islands late evening. There is a low risk of thunderstorms over the eastern central parts of the country during the afternoon and evening, including the Chatham Islands late evening. For eastern parts of Canterbury and Marlborough, there is a moderate risk of thunderstorms in the afternoon, with heavy rain of up to 15 mm/hr, strong gusts of 90 km/h, and small hail. For the lower North Island, there is also the risk of a small tornado and strong wind gusts of up to 100 km/h. No thunderstorms or significant convection expected elsewhere during this period.