Thunderstorms are being forecast across New Zealand on Wednesday with the possibility of heavy rain, hail and tornadoes, MetService says.
The storms will mark the latest rough weather to descend on New Zealand, where this week neighbourhoods from Auckland to Nelson were damaged by a string of tornadoes.
"For the North Island, there is a moderate risk of a few thunderstorms about Northland, Auckland, Coromandel Peninsula, northern Waikato this morning and afternoon, and about the Bay of Plenty this afternoon and evening," MetService said in an alert on Wednesday morning.
"These thunderstorms if they occur could bring localised heavy rain of 10 to 25 mm/h and small hail. Additionally, in the Bay of Plenty, there is the risk of a small tornado."
In the south, parts of Westland faced an enhanced risk of heavy rain, MetService said.
"For the South Island, there is a moderate risk of thunderstorms about far western Tasman, Buller and northern Westland this morning, afternoon and evening.
"There is also a low risk of a few thunderstorms about south Canterbury and north Otago associated with a rain band in the area."
A heavy rain watch has been issued for Westland north of Mt Cook. MetService urged people to keep up to date with the latest forecasts.
Tornadoes not 'unheard of' - expert
NIWA forecaster Chris Brandolino told AM on Tuesday the recent tornadoes weren't "unheard of".
"We average about seven to 10 moderate to strong tornadoes per year across New Zealand," he said.
The mix of warm, humid air and changing wind direction hitting New Zealand was creating perfect conditions for tornadoes, Brandolino said.
"If you have this wind shear in an environment where there are thunderstorms that can often lead to these tornadic type situations."
MetService's short forecast for Wednesday
- Northland to Taranaki, including Coromandel, Bay of Plenty and the central high country: Scattered showers, some heavy with thunderstorms possible, mainly from afternoon
- Gisborne, Hawke's Bay and Wairarapa: Partly cloudy with isolated showers, mainly from afternoon
- Whanganui to Wellington, also Marlborough and Nelson: Fine spells and isolated showers. However, widespread showers returning late on Wednesday afternoon or evening
- Buller and Westland: Rain, heavy at times with possible thunderstorms, easing to a few showers on Wednesday afternoon or evening and clearing Westland
- Canterbury, Otago and Southland: Periods of rain spreading north on Wednesday morning, becoming more widespread in the afternoon and possibly heavy about eastern Otago
- Fiordland: Mainly fine but a few showers linger in the east and about the south coast
- Chatham Islands: Rain with possible thunderstorms, easing to a few showers on Wednesday afternoon.
