A number of severe thunderstorm watches have been issued for parts of the North and South Island today as snowfall closes alpine passes down south.
MetService said an active trough is forecast to pass quickly over the upper North Island on Sunday evening through early Monday morning.
This afternoon a severe thunderstorm warning was issued for the Wellington region, which was lifted just before 6.30pm.
However, MetService warned: “Thunderstorms are expected to affect southern parts of Wellington (near the south coast) between about 6pm and 7pm this evening (Sunday) with heavy rain and hail, but intensities will probably not be severe.”
A West Coast thunderstorm warning that could have caused possible tornadoes was lifted by MetService around 4.30pm. Around the same time the rain radar showed heavy rain starting to move in over Northland.
There are also severe thunderstorm watches for Northland, Auckland, Coromandel Peninsula, and Bay of Plenty, and heavy rain watches for Bay of Plenty east of Whakatāne and Gisborne north of Ruatoria.
Auckland’s severe thunderstorm watch begins at 9pm tonight and lasts until 2am on Monday.
There is a moderate risk of these thunderstorms occurring, and whether these thunderstorms occur or not, MetService said there is a chance of localised downpours of 25-40mm an hour.
“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.”
In the South Island, heavy snowfall has closed Lewis Pass and Arthur’s Pass.
An NZTA spokesperson urged motorists to delay travel through the alpine passes at this time.
“Snowplough trucks are working along both of these routes.”