Area: Northland

Period: 8hrs from 9am - 5pm Fri, 9 May

Forecast: An active trough is expected to bring a period of heavy rain and possible thunderstorms to Northland this morning and afternoon, as detailed in the Heavy Rain Warning. There is a moderate risk of localised Downpours of 25 to 40 mm/h with this trough. 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.

Issued: 8:29am Fri, 9 MayNext update: 2pm Fri, 9 May

Area: Taranaki

Period: 7hrs 30min from 8:30am - 4pm Fri, 9 May

Forecast: An active rainband is expected to bring a period of heavy rain to Taranaki during Friday morning and afternoon. There is a moderate risk of localised Downpours of 25 to 40 mm/h with this rainband. 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.

Issued: 8:29am Fri, 9 MayNext update: 2pm Fri, 9 May

Area: Auckland, Great Barrier Island

Period: 5hrs from 2pm - 7pm Fri, 9 May

Forecast: An active trough is expected to bring a period of heavy rain and possible thunderstorms to Auckland this afternoon and early evening. There is a moderate risk of localised Downpours of 25 to 40 mm/h with this trough, especially in the east of the region. 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.

Issued: 8:29am Fri, 9 MayNext update: 2pm Fri, 9 May

Area: Coromandel Peninsula

Period: 6hrs from 4pm - 10pm Fri, 9 May

Forecast: An active trough is expected to bring a period of heavy rain and possible thunderstorms to the Coromandel Peninsula this afternoon and evening. There is a moderate risk of localised Downpours of 25 to 40 mm/h with this trough. 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.

Issued: 8:29am Fri, 9 MayNext update: 2pm Fri, 9 May

Area: Bay of Plenty, Rotorua

Period: 6hrs from 5pm - 11pm Fri, 9 May

Forecast: An active trough is expected to bring a period of heavy rain and possible thunderstorms to Bay of Plenty this late afternoon and this evening. There is a moderate risk of localised Downpours of 25 to 40 mm/h with this trough. 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.

Issued: 8:29am Fri, 9 MayNext update: 2pm Fri, 9 May

Note: A Severe Thunderstorm Watch means conditions are favourable for severe thunderstorms in and close to the watch area. People in these areas should be on the lookout for threatening weather conditions and monitor for possible Severe Thunderstorm Warnings.

For information on preparing for and keeping safe during a storm, see the Civil Defence Get Ready website

Severe Thunderstorm Criteria

MetService uses the following criteria for severe thunderstoms in New Zealand:

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.