NZ Weather Forum

MetService - Thunderstorm Outlook

A broad trough of low pressure is expected to move eastwards across northern New Zealand during today.

From late this morning till evening, there is mostly a moderate risk of thunderstorms from Taumarunui to Bay of Plenty and northern Gisborne, and extending northwards to Northland. These thunderstorms, if they occur, have the potential to bring localised heavy rain with intensities of 10 to 25 mm/h, and hail 10 to 20 mm in diameter.

However, about Waitomo north of Te Kuiti, Waikato, Bay of Plenty, Coromandel Peninsula, and in the south and southeast of Auckland (from about Howick to Papakura and south of the Manukau Harbour), the thunderstorm risk is high, and there is a moderate risk of thunderstorms becoming SEVERE this afternoon and early evening. These SEVERE THUNDERSTORMS could also bring localised downpours of 25 to 40 mm/h, and the possibility of localised tornadoes.

Rainfall of this intensity can cause surface and/or flash flooding, especially about low-lying areas such as streams, rivers or narrow valleys, and may also lead to slips. Driving conditions will also be hazardous with surface flooding and poor visibility in heavy rain; while tornadoes may cause some structural damage, including damage to trees and power lines, and make driving hazardous. If any tornadoes occur, they will only affect very localised areas.

A SEVERE THUNDERSTORM WATCH is in force.

A lower risk of thunderstorms extends to northern Taranaki, Taihape, the ranges of Hawke's Bay and Gisborne.

No thunderstorms or significant convection expected in other areas of New Zealand during this period.

Issued: 8:30am Sun, 8 Oct
Valid to midnight Sun, 8 Oct